1 What has changed in GDB?
2 (Organized release by release)
4 *** Changes since GDB 7.6
8 ** Frame filters and frame decorators have been added.
12 Nios II ELF nios2*-*-elf
13 Nios II GNU/Linux nios2*-*-linux
17 Like "catch throw", but catches a re-thrown exception.
19 Renamed from old "maint check-symtabs".
21 Perform consistency checks on symtabs.
23 Expand symtabs matching an optional regexp.
26 Display the details of GDB configure-time options.
28 maint set|show per-command
29 maint set|show per-command space
30 maint set|show per-command time
31 maint set|show per-command symtab
32 Enable display of per-command gdb resource usage.
36 set remote trace-status-packet
37 show remote trace-status-packet
38 Set/show the use of remote protocol qTStatus packet.
42 Control display of debugging messages related to Nios II targets.
46 Control whether target-assisted range stepping is enabled.
48 * You can now use a literal value 'unlimited' for options that
49 interpret 0 or -1 as meaning "unlimited". E.g., "set
50 trace-buffer-size unlimited" is now an alias for "set
51 trace-buffer-size -1" and "set height unlimited" is now an alias for
54 * New command-line options
56 Display the details of GDB configure-time options.
58 * The command 'tsave' can now support new option '-ctf' to save trace
59 buffer in Common Trace Format.
61 * Newly installed $prefix/bin/gcore acts as a shell interface for the
64 * GDB now implements the the C++ 'typeid' operator.
66 * The new convenience variable $_exception holds the exception being
67 thrown or caught at an exception-related catchpoint.
69 * The exception-related catchpoints, like "catch throw", now accept a
70 regular expression which can be used to filter exceptions by type.
74 ** The -trace-save MI command can optionally save trace buffer in Common
77 ** The new command -dprintf-insert sets a dynamic printf breakpoint.
79 * New system-wide configuration scripts
80 A GDB installation now provides scripts suitable for use as system-wide
81 configuration scripts for the following systems:
85 * GDB now supports target-assigned range stepping with remote targets.
86 This improves the performance of stepping source lines by reducing
87 the number of control packets from/to GDB. See "New remote packets"
94 The vCont packet supports a new 'r' action, that tells the remote
95 stub to step through an address range itself, without GDB
96 involvemement at each single-step.
98 qXfer:libraries-svr4:read's annex
99 The previously unused annex of the qXfer:libraries-svr4:read packet
100 is now used to support passing an argument list. The remote stub
101 reports support for this argument list to GDB's qSupported query.
102 The defined arguments are "start" and "prev", used to reduce work
103 necessary for library list updating, resulting in significant
106 * New features in the GDB remote stub, GDBserver
108 ** GDBserver now supports target-assisted range stepping. Currently
109 enabled on x86/x86_64 GNU/Linux targets.
111 *** Changes in GDB 7.6
113 * Target record has been renamed to record-full.
114 Record/replay is now enabled with the "record full" command.
115 This also affects settings that are associated with full record/replay
116 that have been moved from "set/show record" to "set/show record full":
118 set|show record full insn-number-max
119 set|show record full stop-at-limit
120 set|show record full memory-query
122 * A new record target "record-btrace" has been added. The new target
123 uses hardware support to record the control-flow of a process. It
124 does not support replaying the execution, but it implements the
125 below new commands for investigating the recorded execution log.
126 This new recording method can be enabled using:
130 The "record-btrace" target is only available on Intel Atom processors
131 and requires a Linux kernel 2.6.32 or later.
133 * Two new commands have been added for record/replay to give information
134 about the recorded execution without having to replay the execution.
135 The commands are only supported by "record btrace".
137 record instruction-history prints the execution history at
138 instruction granularity
140 record function-call-history prints the execution history at
143 * New native configurations
145 ARM AArch64 GNU/Linux aarch64*-*-linux-gnu
146 FreeBSD/powerpc powerpc*-*-freebsd
147 x86_64/Cygwin x86_64-*-cygwin*
148 Tilera TILE-Gx GNU/Linux tilegx*-*-linux-gnu
152 ARM AArch64 aarch64*-*-elf
153 ARM AArch64 GNU/Linux aarch64*-*-linux
154 Lynx 178 PowerPC powerpc-*-lynx*178
155 x86_64/Cygwin x86_64-*-cygwin*
156 Tilera TILE-Gx GNU/Linux tilegx*-*-linux
158 * If the configured location of system.gdbinit file (as given by the
159 --with-system-gdbinit option at configure time) is in the
160 data-directory (as specified by --with-gdb-datadir at configure
161 time) or in one of its subdirectories, then GDB will look for the
162 system-wide init file in the directory specified by the
163 --data-directory command-line option.
165 * New command line options:
167 -nh Disables auto-loading of ~/.gdbinit, but still executes all the
168 other initialization files, unlike -nx which disables all of them.
170 * Removed command line options
172 -epoch This was used by the gdb mode in Epoch, an ancient fork of
175 * The 'ptype' and 'whatis' commands now accept an argument to control
178 * 'info proc' now works on some core files.
182 ** Vectors can be created with gdb.Type.vector.
184 ** Python's atexit.register now works in GDB.
186 ** Types can be pretty-printed via a Python API.
188 ** Python 3 is now supported (in addition to Python 2.4 or later)
190 ** New class gdb.Architecture exposes GDB's internal representation
191 of architecture in the Python API.
193 ** New method Frame.architecture returns the gdb.Architecture object
194 corresponding to the frame's architecture.
196 * New Python-based convenience functions:
198 ** $_memeq(buf1, buf2, length)
199 ** $_streq(str1, str2)
201 ** $_regex(str, regex)
203 * The 'cd' command now defaults to using '~' (the home directory) if not
206 * The C++ ABI now defaults to the GNU v3 ABI. This has been the
207 default for GCC since November 2000.
209 * The command 'forward-search' can now be abbreviated as 'fo'.
211 * The command 'info tracepoints' can now display 'installed on target'
212 or 'not installed on target' for each non-pending location of tracepoint.
214 * New configure options
216 --enable-libmcheck/--disable-libmcheck
217 By default, development versions are built with -lmcheck on hosts
218 that support it, in order to help track memory corruption issues.
219 Release versions, on the other hand, are built without -lmcheck
220 by default. The --enable-libmcheck/--disable-libmcheck configure
221 options allow the user to override that default.
222 --with-babeltrace/--with-babeltrace-include/--with-babeltrace-lib
223 This configure option allows the user to build GDB with
224 libbabeltrace using which GDB can read Common Trace Format data.
226 * New commands (for set/show, see "New options" below)
229 Catch signals. This is similar to "handle", but allows commands and
230 conditions to be attached.
233 List the BFDs known to GDB.
235 python-interactive [command]
237 Start a Python interactive prompt, or evaluate the optional command
238 and print the result of expressions.
241 "py" is a new alias for "python".
243 enable type-printer [name]...
244 disable type-printer [name]...
245 Enable or disable type printers.
249 ** For the Renesas Super-H architecture, the "regs" command has been removed
250 (has been deprecated in GDB 7.5), and "info all-registers" should be used
255 set print type methods (on|off)
256 show print type methods
257 Control whether method declarations are displayed by "ptype".
258 The default is to show them.
260 set print type typedefs (on|off)
261 show print type typedefs
262 Control whether typedef definitions are displayed by "ptype".
263 The default is to show them.
265 set filename-display basename|relative|absolute
266 show filename-display
267 Control the way in which filenames is displayed.
268 The default is "relative", which preserves previous behavior.
270 set trace-buffer-size
271 show trace-buffer-size
272 Request target to change the size of trace buffer.
274 set remote trace-buffer-size-packet auto|on|off
275 show remote trace-buffer-size-packet
276 Control the use of the remote protocol `QTBuffer:size' packet.
280 Control display of debugging messages related to ARM AArch64.
283 set debug coff-pe-read
284 show debug coff-pe-read
285 Control display of debugging messages related to reading of COFF/PE
290 Control display of debugging messages related to Mach-O symbols
293 set debug notification
294 show debug notification
295 Control display of debugging info for async remote notification.
299 ** Command parameter changes are now notified using new async record
300 "=cmd-param-changed".
301 ** Trace frame changes caused by command "tfind" are now notified using
302 new async record "=traceframe-changed".
303 ** The creation, deletion and modification of trace state variables
304 are now notified using new async records "=tsv-created",
305 "=tsv-deleted" and "=tsv-modified".
306 ** The start and stop of process record are now notified using new
307 async record "=record-started" and "=record-stopped".
308 ** Memory changes are now notified using new async record
310 ** The data-disassemble command response will include a "fullname" field
311 containing the absolute file name when source has been requested.
312 ** New optional parameter COUNT added to the "-data-write-memory-bytes"
313 command, to allow pattern filling of memory areas.
314 ** New commands "-catch-load"/"-catch-unload" added for intercepting
315 library load/unload events.
316 ** The response to breakpoint commands and breakpoint async records
317 includes an "installed" field containing a boolean state about each
318 non-pending tracepoint location is whether installed on target or not.
319 ** Output of the "-trace-status" command includes a "trace-file" field
320 containing the name of the trace file being examined. This field is
321 optional, and only present when examining a trace file.
322 ** The "fullname" field is now always present along with the "file" field,
323 even if the file cannot be found by GDB.
325 * GDB now supports the "mini debuginfo" section, .gnu_debugdata.
326 You must have the LZMA library available when configuring GDB for this
327 feature to be enabled. For more information, see:
328 http://fedoraproject.org/wiki/Features/MiniDebugInfo
333 Set the size of trace buffer. The remote stub reports support for this
334 packet to gdb's qSupported query.
337 Enable Branch Trace Store (BTS)-based branch tracing for the current
338 thread. The remote stub reports support for this packet to gdb's
342 Disable branch tracing for the current thread. The remote stub reports
343 support for this packet to gdb's qSupported query.
346 Read the traced branches for the current thread. The remote stub
347 reports support for this packet to gdb's qSupported query.
349 *** Changes in GDB 7.5
351 * GDB now supports x32 ABI. Visit <http://sites.google.com/site/x32abi/>
352 for more x32 ABI info.
354 * GDB now supports access to MIPS DSP registers on Linux targets.
356 * GDB now supports debugging microMIPS binaries.
358 * The "info os" command on GNU/Linux can now display information on
359 several new classes of objects managed by the operating system:
360 "info os procgroups" lists process groups
361 "info os files" lists file descriptors
362 "info os sockets" lists internet-domain sockets
363 "info os shm" lists shared-memory regions
364 "info os semaphores" lists semaphores
365 "info os msg" lists message queues
366 "info os modules" lists loaded kernel modules
368 * GDB now has support for SDT (Static Defined Tracing) probes. Currently,
369 the only implemented backend is for SystemTap probes (<sys/sdt.h>). You
370 can set a breakpoint using the new "-probe, "-pstap" or "-probe-stap"
371 options and inspect the probe arguments using the new $_probe_arg family
372 of convenience variables. You can obtain more information about SystemTap
373 in <http://sourceware.org/systemtap/>.
375 * GDB now supports reversible debugging on ARM, it allows you to
376 debug basic ARM and THUMB instructions, and provides
377 record/replay support.
379 * The option "symbol-reloading" has been deleted as it is no longer used.
383 ** GDB commands implemented in Python can now be put in command class
386 ** The "maint set python print-stack on|off" is now deleted.
388 ** A new class, gdb.printing.FlagEnumerationPrinter, can be used to
389 apply "flag enum"-style pretty-printing to any enum.
391 ** gdb.lookup_symbol can now work when there is no current frame.
393 ** gdb.Symbol now has a 'line' attribute, holding the line number in
394 the source at which the symbol was defined.
396 ** gdb.Symbol now has the new attribute 'needs_frame' and the new
397 method 'value'. The former indicates whether the symbol needs a
398 frame in order to compute its value, and the latter computes the
401 ** A new method 'referenced_value' on gdb.Value objects which can
402 dereference pointer as well as C++ reference values.
404 ** New methods 'global_block' and 'static_block' on gdb.Symtab objects
405 which return the global and static blocks (as gdb.Block objects),
406 of the underlying symbol table, respectively.
408 ** New function gdb.find_pc_line which returns the gdb.Symtab_and_line
409 object associated with a PC value.
411 ** gdb.Symtab_and_line has new attribute 'last' which holds the end
412 of the address range occupied by code for the current source line.
414 * Go language support.
415 GDB now supports debugging programs written in the Go programming
418 * GDBserver now supports stdio connections.
419 E.g. (gdb) target remote | ssh myhost gdbserver - hello
421 * The binary "gdbtui" can no longer be built or installed.
422 Use "gdb -tui" instead.
424 * GDB will now print "flag" enums specially. A flag enum is one where
425 all the enumerator values have no bits in common when pairwise
426 "and"ed. When printing a value whose type is a flag enum, GDB will
427 show all the constants, e.g., for enum E { ONE = 1, TWO = 2}:
428 (gdb) print (enum E) 3
431 * The filename part of a linespec will now match trailing components
432 of a source file name. For example, "break gcc/expr.c:1000" will
433 now set a breakpoint in build/gcc/expr.c, but not
436 * The "info proc" and "generate-core-file" commands will now also
437 work on remote targets connected to GDBserver on Linux.
439 * The command "info catch" has been removed. It has been disabled
442 * The "catch exception" and "catch assert" commands now accept
443 a condition at the end of the command, much like the "break"
444 command does. For instance:
446 (gdb) catch exception Constraint_Error if Barrier = True
448 Previously, it was possible to add a condition to such catchpoints,
449 but it had to be done as a second step, after the catchpoint had been
450 created, using the "condition" command.
452 * The "info static-tracepoint-marker" command will now also work on
453 native Linux targets with in-process agent.
455 * GDB can now set breakpoints on inlined functions.
457 * The .gdb_index section has been updated to include symbols for
458 inlined functions. GDB will ignore older .gdb_index sections by
459 default, which could cause symbol files to be loaded more slowly
460 until their .gdb_index sections can be recreated. The new command
461 "set use-deprecated-index-sections on" will cause GDB to use any older
462 .gdb_index sections it finds. This will restore performance, but the
463 ability to set breakpoints on inlined functions will be lost in symbol
464 files with older .gdb_index sections.
466 The .gdb_index section has also been updated to record more information
467 about each symbol. This speeds up the "info variables", "info functions"
468 and "info types" commands when used with programs having the .gdb_index
469 section, as well as speeding up debugging with shared libraries using
470 the .gdb_index section.
472 * Ada support for GDB/MI Variable Objects has been added.
474 * GDB can now support 'breakpoint always-inserted mode' in 'record'
479 ** New command -info-os is the MI equivalent of "info os".
481 ** Output logs ("set logging" and related) now include MI output.
485 ** "set use-deprecated-index-sections on|off"
486 "show use-deprecated-index-sections on|off"
487 Controls the use of deprecated .gdb_index sections.
489 ** "catch load" and "catch unload" can be used to stop when a shared
490 library is loaded or unloaded, respectively.
492 ** "enable count" can be used to auto-disable a breakpoint after
495 ** "info vtbl" can be used to show the virtual method tables for
496 C++ and Java objects.
498 ** "explore" and its sub commands "explore value" and "explore type"
499 can be used to reccursively explore values and types of
500 expressions. These commands are available only if GDB is
501 configured with '--with-python'.
503 ** "info auto-load" shows status of all kinds of auto-loaded files,
504 "info auto-load gdb-scripts" shows status of auto-loading GDB canned
505 sequences of commands files, "info auto-load python-scripts"
506 shows status of auto-loading Python script files,
507 "info auto-load local-gdbinit" shows status of loading init file
508 (.gdbinit) from current directory and "info auto-load libthread-db" shows
509 status of inferior specific thread debugging shared library loading.
511 ** "info auto-load-scripts", "set auto-load-scripts on|off"
512 and "show auto-load-scripts" commands have been deprecated, use their
513 "info auto-load python-scripts", "set auto-load python-scripts on|off"
514 and "show auto-load python-scripts" counterparts instead.
516 ** "dprintf location,format,args..." creates a dynamic printf, which
517 is basically a breakpoint that does a printf and immediately
518 resumes your program's execution, so it is like a printf that you
519 can insert dynamically at runtime instead of at compiletime.
521 ** "set print symbol"
523 Controls whether GDB attempts to display the symbol, if any,
524 corresponding to addresses it prints. This defaults to "on", but
525 you can set it to "off" to restore GDB's previous behavior.
527 * Deprecated commands
529 ** For the Renesas Super-H architecture, the "regs" command has been
530 deprecated, and "info all-registers" should be used instead.
534 Renesas RL78 rl78-*-elf
535 HP OpenVMS ia64 ia64-hp-openvms*
537 * GDBserver supports evaluation of breakpoint conditions. When
538 support is advertised by GDBserver, GDB may be told to send the
539 breakpoint conditions in bytecode form to GDBserver. GDBserver
540 will only report the breakpoint trigger to GDB when its condition
546 show mips compression
547 Select the compressed ISA encoding used in functions that have no symbol
548 information available. The encoding can be set to either of:
551 and is updated automatically from ELF file flags if available.
553 set breakpoint condition-evaluation
554 show breakpoint condition-evaluation
555 Control whether breakpoint conditions are evaluated by GDB ("host") or by
556 GDBserver ("target"). Default option "auto" chooses the most efficient
558 This option can improve debugger efficiency depending on the speed of the
562 Disable auto-loading globally.
565 Show auto-loading setting of all kinds of auto-loaded files.
567 set auto-load gdb-scripts on|off
568 show auto-load gdb-scripts
569 Control auto-loading of GDB canned sequences of commands files.
571 set auto-load python-scripts on|off
572 show auto-load python-scripts
573 Control auto-loading of Python script files.
575 set auto-load local-gdbinit on|off
576 show auto-load local-gdbinit
577 Control loading of init file (.gdbinit) from current directory.
579 set auto-load libthread-db on|off
580 show auto-load libthread-db
581 Control auto-loading of inferior specific thread debugging shared library.
583 set auto-load scripts-directory <dir1>[:<dir2>...]
584 show auto-load scripts-directory
585 Set a list of directories from which to load auto-loaded scripts.
586 Automatically loaded Python scripts and GDB scripts are located in one
587 of the directories listed by this option.
588 The delimiter (':' above) may differ according to the host platform.
590 set auto-load safe-path <dir1>[:<dir2>...]
591 show auto-load safe-path
592 Set a list of directories from which it is safe to auto-load files.
593 The delimiter (':' above) may differ according to the host platform.
595 set debug auto-load on|off
597 Control display of debugging info for auto-loading the files above.
599 set dprintf-style gdb|call|agent
601 Control the way in which a dynamic printf is performed; "gdb"
602 requests a GDB printf command, while "call" causes dprintf to call a
603 function in the inferior. "agent" requests that the target agent
604 (such as GDBserver) do the printing.
606 set dprintf-function <expr>
607 show dprintf-function
608 set dprintf-channel <expr>
610 Set the function and optional first argument to the call when using
611 the "call" style of dynamic printf.
613 set disconnected-dprintf on|off
614 show disconnected-dprintf
615 Control whether agent-style dynamic printfs continue to be in effect
616 after GDB disconnects.
618 * New configure options
621 Configure default value for the 'set auto-load scripts-directory'
622 setting above. It defaults to '$debugdir:$datadir/auto-load',
623 $debugdir representing global debugging info directories (available
624 via 'show debug-file-directory') and $datadir representing GDB's data
625 directory (available via 'show data-directory').
627 --with-auto-load-safe-path
628 Configure default value for the 'set auto-load safe-path' setting
629 above. It defaults to the --with-auto-load-dir setting.
631 --without-auto-load-safe-path
632 Set 'set auto-load safe-path' to '/', effectively disabling this
637 z0/z1 conditional breakpoints extension
639 The z0/z1 breakpoint insertion packets have been extended to carry
640 a list of conditional expressions over to the remote stub depending on the
641 condition evaluation mode. The use of this extension can be controlled
642 via the "set remote conditional-breakpoints-packet" command.
646 Specify the signals which the remote stub may pass to the debugged
647 program without GDB involvement.
649 * New command line options
651 --init-command=FILE, -ix Like --command, -x but execute it
652 before loading inferior.
653 --init-eval-command=COMMAND, -iex Like --eval-command=COMMAND, -ex but
654 execute it before loading inferior.
656 *** Changes in GDB 7.4
658 * GDB now handles ambiguous linespecs more consistently; the existing
659 FILE:LINE support has been expanded to other types of linespecs. A
660 breakpoint will now be set on all matching locations in all
661 inferiors, and locations will be added or removed according to
664 * GDB now allows you to skip uninteresting functions and files when
665 stepping with the "skip function" and "skip file" commands.
667 * GDB has two new commands: "set remote hardware-watchpoint-length-limit"
668 and "show remote hardware-watchpoint-length-limit". These allows to
669 set or show the maximum length limit (in bytes) of a remote
670 target hardware watchpoint.
672 This allows e.g. to use "unlimited" hardware watchpoints with the
673 gdbserver integrated in Valgrind version >= 3.7.0. Such Valgrind
674 watchpoints are slower than real hardware watchpoints but are
675 significantly faster than gdb software watchpoints.
679 ** The register_pretty_printer function in module gdb.printing now takes
680 an optional `replace' argument. If True, the new printer replaces any
683 ** The "maint set python print-stack on|off" command has been
684 deprecated and will be deleted in GDB 7.5.
685 A new command: "set python print-stack none|full|message" has
686 replaced it. Additionally, the default for "print-stack" is
687 now "message", which just prints the error message without
690 ** A prompt substitution hook (prompt_hook) is now available to the
693 ** A new Python module, gdb.prompt has been added to the GDB Python
694 modules library. This module provides functionality for
695 escape sequences in prompts (used by set/show
696 extended-prompt). These escape sequences are replaced by their
699 ** Python commands and convenience-functions located in
700 'data-directory'/python/gdb/command and
701 'data-directory'/python/gdb/function are now automatically loaded
704 ** Blocks now provide four new attributes. global_block and
705 static_block will return the global and static blocks
706 respectively. is_static and is_global are boolean attributes
707 that indicate if the block is one of those two types.
709 ** Symbols now provide the "type" attribute, the type of the symbol.
711 ** The "gdb.breakpoint" function has been deprecated in favor of
714 ** A new class "gdb.FinishBreakpoint" is provided to catch the return
715 of a function. This class is based on the "finish" command
716 available in the CLI.
718 ** Type objects for struct and union types now allow access to
719 the fields using standard Python dictionary (mapping) methods.
720 For example, "some_type['myfield']" now works, as does
723 ** A new event "gdb.new_objfile" has been added, triggered by loading a
726 ** A new function, "deep_items" has been added to the gdb.types
727 module in the GDB Python modules library. This function returns
728 an iterator over the fields of a struct or union type. Unlike
729 the standard Python "iteritems" method, it will recursively traverse
730 any anonymous fields.
734 ** "*stopped" events can report several new "reason"s, such as
737 ** Breakpoint changes are now notified using new async records, like
738 "=breakpoint-modified".
740 ** New command -ada-task-info.
742 * libthread-db-search-path now supports two special values: $sdir and $pdir.
743 $sdir specifies the default system locations of shared libraries.
744 $pdir specifies the directory where the libpthread used by the application
747 GDB no longer looks in $sdir and $pdir after it has searched the directories
748 mentioned in libthread-db-search-path. If you want to search those
749 directories, they must be specified in libthread-db-search-path.
750 The default value of libthread-db-search-path on GNU/Linux and Solaris
751 systems is now "$sdir:$pdir".
753 $pdir is not supported by gdbserver, it is currently ignored.
754 $sdir is supported by gdbserver.
756 * New configure option --with-iconv-bin.
757 When using the internationalization support like the one in the GNU C
758 library, GDB will invoke the "iconv" program to get a list of supported
759 character sets. If this program lives in a non-standard location, one can
760 use this option to specify where to find it.
762 * When natively debugging programs on PowerPC BookE processors running
763 a Linux kernel version 2.6.34 or later, GDB supports masked hardware
764 watchpoints, which specify a mask in addition to an address to watch.
765 The mask specifies that some bits of an address (the bits which are
766 reset in the mask) should be ignored when matching the address accessed
767 by the inferior against the watchpoint address. See the "PowerPC Embedded"
768 section in the user manual for more details.
770 * The new option --once causes GDBserver to stop listening for connections once
771 the first connection is made. The listening port used by GDBserver will
772 become available after that.
774 * New commands "info macros" and "alias" have been added.
776 * New function parameters suffix @entry specifies value of function parameter
777 at the time the function got called. Entry values are available only since
783 "!" is now an alias of the "shell" command.
784 Note that no space is needed between "!" and SHELL COMMAND.
788 watch EXPRESSION mask MASK_VALUE
789 The watch command now supports the mask argument which allows creation
790 of masked watchpoints, if the current architecture supports this feature.
792 info auto-load-scripts [REGEXP]
793 This command was formerly named "maintenance print section-scripts".
794 It is now generally useful and is no longer a maintenance-only command.
796 info macro [-all] [--] MACRO
797 The info macro command has new options `-all' and `--'. The first for
798 printing all definitions of a macro. The second for explicitly specifying
799 the end of arguments and the beginning of the macro name in case the macro
800 name starts with a hyphen.
802 collect[/s] EXPRESSIONS
803 The tracepoint collect command now takes an optional modifier "/s"
804 that directs it to dereference pointer-to-character types and
805 collect the bytes of memory up to a zero byte. The behavior is
806 similar to what you see when you use the regular print command on a
807 string. An optional integer following the "/s" sets a bound on the
808 number of bytes that will be collected.
811 The trace start command now interprets any supplied arguments as a
812 note to be recorded with the trace run, with an effect similar to
813 setting the variable trace-notes.
816 The trace stop command now interprets any arguments as a note to be
817 mentioned along with the tstatus report that the trace was stopped
818 with a command. The effect is similar to setting the variable
821 * Tracepoints can now be enabled and disabled at any time after a trace
822 experiment has been started using the standard "enable" and "disable"
823 commands. It is now possible to start a trace experiment with no enabled
824 tracepoints; GDB will display a warning, but will allow the experiment to
825 begin, assuming that tracepoints will be enabled as needed while the trace
828 * Fast tracepoints on 32-bit x86-architectures can now be placed at
829 locations with 4-byte instructions, when they were previously
830 limited to locations with instructions of 5 bytes or longer.
834 set debug dwarf2-read
835 show debug dwarf2-read
836 Turns on or off display of debugging messages related to reading
837 DWARF debug info. The default is off.
839 set debug symtab-create
840 show debug symtab-create
841 Turns on or off display of debugging messages related to symbol table
842 creation. The default is off.
846 Set the GDB prompt, and allow escape sequences to be inserted to
847 display miscellaneous information (see 'help set extended-prompt'
848 for the list of sequences). This prompt (and any information
849 accessed through the escape sequences) is updated every time the
852 set print entry-values (both|compact|default|if-needed|no|only|preferred)
853 show print entry-values
854 Set printing of frame argument values at function entry. In some cases
855 GDB can determine the value of function argument which was passed by the
856 function caller, even if the value was modified inside the called function.
858 set debug entry-values
859 show debug entry-values
860 Control display of debugging info for determining frame argument values at
861 function entry and virtual tail call frames.
863 set basenames-may-differ
864 show basenames-may-differ
865 Set whether a source file may have multiple base names.
866 (A "base name" is the name of a file with the directory part removed.
867 Example: The base name of "/home/user/hello.c" is "hello.c".)
868 If set, GDB will canonicalize file names (e.g., expand symlinks)
869 before comparing them. Canonicalization is an expensive operation,
870 but it allows the same file be known by more than one base name.
871 If not set (the default), all source files are assumed to have just
872 one base name, and gdb will do file name comparisons more efficiently.
878 Set a user name and notes for the current and any future trace runs.
879 This is useful for long-running and/or disconnected traces, to
880 inform others (or yourself) as to who is running the trace, supply
881 contact information, or otherwise explain what is going on.
884 show trace-stop-notes
885 Set a note attached to the trace run, that is displayed when the
886 trace has been stopped by a tstop command. This is useful for
887 instance as an explanation, if you are stopping a trace run that was
888 started by someone else.
894 Dynamically enable a tracepoint in a started trace experiment.
898 Dynamically disable a tracepoint in a started trace experiment.
902 Set the user and notes of the trace run.
906 Query the current status of a tracepoint.
910 Query the minimum length of instruction at which a fast tracepoint may
913 * Dcache size (number of lines) and line-size are now runtime-configurable
914 via "set dcache line" and "set dcache line-size" commands.
918 Texas Instruments TMS320C6x tic6x-*-*
922 Renesas RL78 rl78-*-elf
924 *** Changes in GDB 7.3.1
926 * The build failure for NetBSD and OpenBSD targets have now been fixed.
928 *** Changes in GDB 7.3
930 * GDB has a new command: "thread find [REGEXP]".
931 It finds the thread id whose name, target id, or thread extra info
932 matches the given regular expression.
934 * The "catch syscall" command now works on mips*-linux* targets.
936 * The -data-disassemble MI command now supports modes 2 and 3 for
937 dumping the instruction opcodes.
939 * New command line options
941 -data-directory DIR Specify DIR as the "data-directory".
942 This is mostly for testing purposes.
944 * The "maint set python auto-load on|off" command has been renamed to
945 "set auto-load-scripts on|off".
947 * GDB has a new command: "set directories".
948 It is like the "dir" command except that it replaces the
949 source path list instead of augmenting it.
951 * GDB now understands thread names.
953 On GNU/Linux, "info threads" will display the thread name as set by
954 prctl or pthread_setname_np.
956 There is also a new command, "thread name", which can be used to
957 assign a name internally for GDB to display.
960 Initial support for the OpenCL C language (http://www.khronos.org/opencl)
961 has been integrated into GDB.
965 ** The function gdb.Write now accepts an optional keyword 'stream'.
966 This keyword, when provided, will direct the output to either
967 stdout, stderr, or GDB's logging output.
969 ** Parameters can now be be sub-classed in Python, and in particular
970 you may implement the get_set_doc and get_show_doc functions.
971 This improves how Parameter set/show documentation is processed
972 and allows for more dynamic content.
974 ** Symbols, Symbol Table, Symbol Table and Line, Object Files,
975 Inferior, Inferior Thread, Blocks, and Block Iterator APIs now
976 have an is_valid method.
978 ** Breakpoints can now be sub-classed in Python, and in particular
979 you may implement a 'stop' function that is executed each time
980 the inferior reaches that breakpoint.
982 ** New function gdb.lookup_global_symbol looks up a global symbol.
984 ** GDB values in Python are now callable if the value represents a
985 function. For example, if 'some_value' represents a function that
986 takes two integer parameters and returns a value, you can call
987 that function like so:
989 result = some_value (10,20)
991 ** Module gdb.types has been added.
992 It contains a collection of utilities for working with gdb.Types objects:
993 get_basic_type, has_field, make_enum_dict.
995 ** Module gdb.printing has been added.
996 It contains utilities for writing and registering pretty-printers.
997 New classes: PrettyPrinter, SubPrettyPrinter,
998 RegexpCollectionPrettyPrinter.
999 New function: register_pretty_printer.
1001 ** New commands "info pretty-printers", "enable pretty-printer" and
1002 "disable pretty-printer" have been added.
1004 ** gdb.parameter("directories") is now available.
1006 ** New function gdb.newest_frame returns the newest frame in the
1009 ** The gdb.InferiorThread class has a new "name" attribute. This
1010 holds the thread's name.
1012 ** Python Support for Inferior events.
1013 Python scripts can add observers to be notified of events
1014 occurring in the process being debugged.
1015 The following events are currently supported:
1016 - gdb.events.cont Continue event.
1017 - gdb.events.exited Inferior exited event.
1018 - gdb.events.stop Signal received, and Breakpoint hit events.
1022 ** GDB now puts template parameters in scope when debugging in an
1023 instantiation. For example, if you have:
1025 template<int X> int func (void) { return X; }
1027 then if you step into func<5>, "print X" will show "5". This
1028 feature requires proper debuginfo support from the compiler; it
1029 was added to GCC 4.5.
1031 ** The motion commands "next", "finish", "until", and "advance" now
1032 work better when exceptions are thrown. In particular, GDB will
1033 no longer lose control of the inferior; instead, the GDB will
1034 stop the inferior at the point at which the exception is caught.
1035 This functionality requires a change in the exception handling
1036 code that was introduced in GCC 4.5.
1038 * GDB now follows GCC's rules on accessing volatile objects when
1039 reading or writing target state during expression evaluation.
1040 One notable difference to prior behavior is that "print x = 0"
1041 no longer generates a read of x; the value of the assignment is
1042 now always taken directly from the value being assigned.
1044 * GDB now has some support for using labels in the program's source in
1045 linespecs. For instance, you can use "advance label" to continue
1046 execution to a label.
1048 * GDB now has support for reading and writing a new .gdb_index
1049 section. This section holds a fast index of DWARF debugging
1050 information and can be used to greatly speed up GDB startup and
1051 operation. See the documentation for `save gdb-index' for details.
1053 * The "watch" command now accepts an optional "-location" argument.
1054 When used, this causes GDB to watch the memory referred to by the
1055 expression. Such a watchpoint is never deleted due to it going out
1058 * GDB now supports thread debugging of core dumps on GNU/Linux.
1060 GDB now activates thread debugging using the libthread_db library
1061 when debugging GNU/Linux core dumps, similarly to when debugging
1062 live processes. As a result, when debugging a core dump file, GDB
1063 is now able to display pthread_t ids of threads. For example, "info
1064 threads" shows the same output as when debugging the process when it
1065 was live. In earlier releases, you'd see something like this:
1068 * 1 LWP 6780 main () at main.c:10
1070 While now you see this:
1073 * 1 Thread 0x7f0f5712a700 (LWP 6780) main () at main.c:10
1075 It is also now possible to inspect TLS variables when debugging core
1078 When debugging a core dump generated on a machine other than the one
1079 used to run GDB, you may need to point GDB at the correct
1080 libthread_db library with the "set libthread-db-search-path"
1081 command. See the user manual for more details on this command.
1083 * When natively debugging programs on PowerPC BookE processors running
1084 a Linux kernel version 2.6.34 or later, GDB supports ranged breakpoints,
1085 which stop execution of the inferior whenever it executes an instruction
1086 at any address within the specified range. See the "PowerPC Embedded"
1087 section in the user manual for more details.
1089 * New features in the GDB remote stub, GDBserver
1091 ** GDBserver is now supported on PowerPC LynxOS (versions 4.x and 5.x),
1092 and i686 LynxOS (version 5.x).
1094 ** GDBserver is now supported on Blackfin Linux.
1096 * New native configurations
1098 ia64 HP-UX ia64-*-hpux*
1102 Analog Devices, Inc. Blackfin Processor bfin-*
1104 * Ada task switching is now supported on sparc-elf targets when
1105 debugging a program using the Ravenscar Profile. For more information,
1106 see the "Tasking Support when using the Ravenscar Profile" section
1107 in the GDB user manual.
1109 * Guile support was removed.
1111 * New features in the GNU simulator
1113 ** The --map-info flag lists all known core mappings.
1115 ** CFI flashes may be simulated via the "cfi" device.
1117 *** Changes in GDB 7.2
1119 * Shared library support for remote targets by default
1121 When GDB is configured for a generic, non-OS specific target, like
1122 for example, --target=arm-eabi or one of the many *-*-elf targets,
1123 GDB now queries remote stubs for loaded shared libraries using the
1124 `qXfer:libraries:read' packet. Previously, shared library support
1125 was always disabled for such configurations.
1129 ** Argument Dependent Lookup (ADL)
1131 In C++ ADL lookup directs function search to the namespaces of its
1132 arguments even if the namespace has not been imported.
1142 Here the compiler will search for `foo' in the namespace of 'b'
1143 and find A::foo. GDB now supports this. This construct is commonly
1144 used in the Standard Template Library for operators.
1146 ** Improved User Defined Operator Support
1148 In addition to member operators, GDB now supports lookup of operators
1149 defined in a namespace and imported with a `using' directive, operators
1150 defined in the global scope, operators imported implicitly from an
1151 anonymous namespace, and the ADL operators mentioned in the previous
1153 GDB now also supports proper overload resolution for all the previously
1154 mentioned flavors of operators.
1156 ** static const class members
1158 Printing of static const class members that are initialized in the
1159 class definition has been fixed.
1161 * Windows Thread Information Block access.
1163 On Windows targets, GDB now supports displaying the Windows Thread
1164 Information Block (TIB) structure. This structure is visible either
1165 by using the new command `info w32 thread-information-block' or, by
1166 dereferencing the new convenience variable named `$_tlb', a
1167 thread-specific pointer to the TIB. This feature is also supported
1168 when remote debugging using GDBserver.
1170 * Static tracepoints
1172 Static tracepoints are calls in the user program into a tracing
1173 library. One such library is a port of the LTTng kernel tracer to
1174 userspace --- UST (LTTng Userspace Tracer, http://lttng.org/ust).
1175 When debugging with GDBserver, GDB now supports combining the GDB
1176 tracepoint machinery with such libraries. For example: the user can
1177 use GDB to probe a static tracepoint marker (a call from the user
1178 program into the tracing library) with the new "strace" command (see
1179 "New commands" below). This creates a "static tracepoint" in the
1180 breakpoint list, that can be manipulated with the same feature set
1181 as fast and regular tracepoints. E.g., collect registers, local and
1182 global variables, collect trace state variables, and define
1183 tracepoint conditions. In addition, the user can collect extra
1184 static tracepoint marker specific data, by collecting the new
1185 $_sdata internal variable. When analyzing the trace buffer, you can
1186 inspect $_sdata like any other variable available to GDB. For more
1187 information, see the "Tracepoints" chapter in GDB user manual. New
1188 remote packets have been defined to support static tracepoints, see
1189 the "New remote packets" section below.
1191 * Better reconstruction of tracepoints after disconnected tracing
1193 GDB will attempt to download the original source form of tracepoint
1194 definitions when starting a trace run, and then will upload these
1195 upon reconnection to the target, resulting in a more accurate
1196 reconstruction of the tracepoints that are in use on the target.
1200 You can now exercise direct control over the ways that GDB can
1201 affect your program. For instance, you can disallow the setting of
1202 breakpoints, so that the program can run continuously (assuming
1203 non-stop mode). In addition, the "observer" variable is available
1204 to switch all of the different controls; in observer mode, GDB
1205 cannot affect the target's behavior at all, which is useful for
1206 tasks like diagnosing live systems in the field.
1208 * The new convenience variable $_thread holds the number of the
1211 * New remote packets
1215 Return the address of the Windows Thread Information Block of a given thread.
1219 In response to several of the tracepoint packets, the target may now
1220 also respond with a number of intermediate `qRelocInsn' request
1221 packets before the final result packet, to have GDB handle
1222 relocating an instruction to execute at a different address. This
1223 is particularly useful for stubs that support fast tracepoints. GDB
1224 reports support for this feature in the qSupported packet.
1228 List static tracepoint markers in the target program.
1232 List static tracepoint markers at a given address in the target
1235 qXfer:statictrace:read
1237 Read the static trace data collected (by a `collect $_sdata'
1238 tracepoint action). The remote stub reports support for this packet
1239 to gdb's qSupported query.
1243 Send the current settings of GDB's permission flags.
1247 Send part of the source (textual) form of a tracepoint definition,
1248 which includes location, conditional, and action list.
1250 * The source command now accepts a -s option to force searching for the
1251 script in the source search path even if the script name specifies
1254 * New features in the GDB remote stub, GDBserver
1256 - GDBserver now support tracepoints (including fast tracepoints, and
1257 static tracepoints). The feature is currently supported by the
1258 i386-linux and amd64-linux builds. See the "Tracepoints support
1259 in gdbserver" section in the manual for more information.
1261 GDBserver JIT compiles the tracepoint's conditional agent
1262 expression bytecode into native code whenever possible for low
1263 overhead dynamic tracepoints conditionals. For such tracepoints,
1264 an expression that examines program state is evaluated when the
1265 tracepoint is reached, in order to determine whether to capture
1266 trace data. If the condition is simple and false, processing the
1267 tracepoint finishes very quickly and no data is gathered.
1269 GDBserver interfaces with the UST (LTTng Userspace Tracer) library
1270 for static tracepoints support.
1272 - GDBserver now supports x86_64 Windows 64-bit debugging.
1274 * GDB now sends xmlRegisters= in qSupported packet to indicate that
1275 it understands register description.
1277 * The --batch flag now disables pagination and queries.
1279 * X86 general purpose registers
1281 GDB now supports reading/writing byte, word and double-word x86
1282 general purpose registers directly. This means you can use, say,
1283 $ah or $ax to refer, respectively, to the byte register AH and
1284 16-bit word register AX that are actually portions of the 32-bit
1285 register EAX or 64-bit register RAX.
1287 * The `commands' command now accepts a range of breakpoints to modify.
1288 A plain `commands' following a command that creates multiple
1289 breakpoints affects all the breakpoints set by that command. This
1290 applies to breakpoints set by `rbreak', and also applies when a
1291 single `break' command creates multiple breakpoints (e.g.,
1292 breakpoints on overloaded c++ functions).
1294 * The `rbreak' command now accepts a filename specification as part of
1295 its argument, limiting the functions selected by the regex to those
1296 in the specified file.
1298 * Support for remote debugging Windows and SymbianOS shared libraries
1299 from Unix hosts has been improved. Non Windows GDB builds now can
1300 understand target reported file names that follow MS-DOS based file
1301 system semantics, such as file names that include drive letters and
1302 use the backslash character as directory separator. This makes it
1303 possible to transparently use the "set sysroot" and "set
1304 solib-search-path" on Unix hosts to point as host copies of the
1305 target's shared libraries. See the new command "set
1306 target-file-system-kind" described below, and the "Commands to
1307 specify files" section in the user manual for more information.
1311 eval template, expressions...
1312 Convert the values of one or more expressions under the control
1313 of the string template to a command line, and call it.
1315 set target-file-system-kind unix|dos-based|auto
1316 show target-file-system-kind
1317 Set or show the assumed file system kind for target reported file
1320 save breakpoints <filename>
1321 Save all current breakpoint definitions to a file suitable for use
1322 in a later debugging session. To read the saved breakpoint
1323 definitions, use the `source' command.
1325 `save tracepoints' is a new alias for `save-tracepoints'. The latter
1328 info static-tracepoint-markers
1329 Display information about static tracepoint markers in the target.
1331 strace FN | FILE:LINE | *ADDR | -m MARKER_ID
1332 Define a static tracepoint by probing a marker at the given
1333 function, line, address, or marker ID.
1337 Enable and disable observer mode.
1339 set may-write-registers on|off
1340 set may-write-memory on|off
1341 set may-insert-breakpoints on|off
1342 set may-insert-tracepoints on|off
1343 set may-insert-fast-tracepoints on|off
1344 set may-interrupt on|off
1345 Set individual permissions for GDB effects on the target. Note that
1346 some of these settings can have undesirable or surprising
1347 consequences, particularly when changed in the middle of a session.
1348 For instance, disabling the writing of memory can prevent
1349 breakpoints from being inserted, cause single-stepping to fail, or
1350 even crash your program, if you disable after breakpoints have been
1351 inserted. However, GDB should not crash.
1353 set record memory-query on|off
1354 show record memory-query
1355 Control whether to stop the inferior if memory changes caused
1356 by an instruction cannot be recorded.
1361 The disassemble command now supports "start,+length" form of two arguments.
1365 ** GDB now provides a new directory location, called the python directory,
1366 where Python scripts written for GDB can be installed. The location
1367 of that directory is <data-directory>/python, where <data-directory>
1368 is the GDB data directory. For more details, see section `Scripting
1369 GDB using Python' in the manual.
1371 ** The GDB Python API now has access to breakpoints, symbols, symbol
1372 tables, program spaces, inferiors, threads and frame's code blocks.
1373 Additionally, GDB Parameters can now be created from the API, and
1374 manipulated via set/show in the CLI.
1376 ** New functions gdb.target_charset, gdb.target_wide_charset,
1377 gdb.progspaces, gdb.current_progspace, and gdb.string_to_argv.
1379 ** New exception gdb.GdbError.
1381 ** Pretty-printers are now also looked up in the current program space.
1383 ** Pretty-printers can now be individually enabled and disabled.
1385 ** GDB now looks for names of Python scripts to auto-load in a
1386 special section named `.debug_gdb_scripts', in addition to looking
1387 for a OBJFILE-gdb.py script when OBJFILE is read by the debugger.
1389 * Tracepoint actions were unified with breakpoint commands. In particular,
1390 there are no longer differences in "info break" output for breakpoints and
1391 tracepoints and the "commands" command can be used for both tracepoints and
1392 regular breakpoints.
1396 ARM Symbian arm*-*-symbianelf*
1398 * D language support.
1399 GDB now supports debugging programs written in the D programming
1402 * GDB now supports the extended ptrace interface for PowerPC which is
1403 available since Linux kernel version 2.6.34. This automatically enables
1404 any hardware breakpoints and additional hardware watchpoints available in
1405 the processor. The old ptrace interface exposes just one hardware
1406 watchpoint and no hardware breakpoints.
1408 * GDB is now able to use the Data Value Compare (DVC) register available on
1409 embedded PowerPC processors to implement in hardware simple watchpoint
1410 conditions of the form:
1412 watch ADDRESS|VARIABLE if ADDRESS|VARIABLE == CONSTANT EXPRESSION
1414 This works in native GDB running on Linux kernels with the extended ptrace
1415 interface mentioned above.
1417 *** Changes in GDB 7.1
1421 ** Namespace Support
1423 GDB now supports importing of namespaces in C++. This enables the
1424 user to inspect variables from imported namespaces. Support for
1425 namepace aliasing has also been added. So, if a namespace is
1426 aliased in the current scope (e.g. namepace C=A; ) the user can
1427 print variables using the alias (e.g. (gdb) print C::x).
1431 All known bugs relating to the printing of virtual base class were
1432 fixed. It is now possible to call overloaded static methods using a
1437 The C++ cast operators static_cast<>, dynamic_cast<>, const_cast<>,
1438 and reinterpret_cast<> are now handled by the C++ expression parser.
1442 Xilinx MicroBlaze microblaze-*-*
1447 Xilinx MicroBlaze microblaze
1450 * Multi-program debugging.
1452 GDB now has support for multi-program (a.k.a. multi-executable or
1453 multi-exec) debugging. This allows for debugging multiple inferiors
1454 simultaneously each running a different program under the same GDB
1455 session. See "Debugging Multiple Inferiors and Programs" in the
1456 manual for more information. This implied some user visible changes
1457 in the multi-inferior support. For example, "info inferiors" now
1458 lists inferiors that are not running yet or that have exited
1459 already. See also "New commands" and "New options" below.
1461 * New tracing features
1463 GDB's tracepoint facility now includes several new features:
1465 ** Trace state variables
1467 GDB tracepoints now include support for trace state variables, which
1468 are variables managed by the target agent during a tracing
1469 experiment. They are useful for tracepoints that trigger each
1470 other, so for instance one tracepoint can count hits in a variable,
1471 and then a second tracepoint has a condition that is true when the
1472 count reaches a particular value. Trace state variables share the
1473 $-syntax of GDB convenience variables, and can appear in both
1474 tracepoint actions and condition expressions. Use the "tvariable"
1475 command to create, and "info tvariables" to view; see "Trace State
1476 Variables" in the manual for more detail.
1480 GDB now includes an option for defining fast tracepoints, which
1481 targets may implement more efficiently, such as by installing a jump
1482 into the target agent rather than a trap instruction. The resulting
1483 speedup can be by two orders of magnitude or more, although the
1484 tradeoff is that some program locations on some target architectures
1485 might not allow fast tracepoint installation, for instance if the
1486 instruction to be replaced is shorter than the jump. To request a
1487 fast tracepoint, use the "ftrace" command, with syntax identical to
1488 the regular trace command.
1490 ** Disconnected tracing
1492 It is now possible to detach GDB from the target while it is running
1493 a trace experiment, then reconnect later to see how the experiment
1494 is going. In addition, a new variable disconnected-tracing lets you
1495 tell the target agent whether to continue running a trace if the
1496 connection is lost unexpectedly.
1500 GDB now has the ability to save the trace buffer into a file, and
1501 then use that file as a target, similarly to you can do with
1502 corefiles. You can select trace frames, print data that was
1503 collected in them, and use tstatus to display the state of the
1504 tracing run at the moment that it was saved. To create a trace
1505 file, use "tsave <filename>", and to use it, do "target tfile
1508 ** Circular trace buffer
1510 You can ask the target agent to handle the trace buffer as a
1511 circular buffer, discarding the oldest trace frames to make room for
1512 newer ones, by setting circular-trace-buffer to on. This feature may
1513 not be available for all target agents.
1518 The disassemble command, when invoked with two arguments, now requires
1519 the arguments to be comma-separated.
1522 The info variables command now displays variable definitions. Files
1523 which only declare a variable are not shown.
1526 The source command is now capable of sourcing Python scripts.
1527 This feature is dependent on the debugger being build with Python
1530 Related to this enhancement is also the introduction of a new command
1531 "set script-extension" (see below).
1533 * New commands (for set/show, see "New options" below)
1535 record save [<FILENAME>]
1536 Save a file (in core file format) containing the process record
1537 execution log for replay debugging at a later time.
1539 record restore <FILENAME>
1540 Restore the process record execution log that was saved at an
1541 earlier time, for replay debugging.
1543 add-inferior [-copies <N>] [-exec <FILENAME>]
1546 clone-inferior [-copies <N>] [ID]
1547 Make a new inferior ready to execute the same program another
1548 inferior has loaded.
1553 maint info program-spaces
1554 List the program spaces loaded into GDB.
1556 set remote interrupt-sequence [Ctrl-C | BREAK | BREAK-g]
1557 show remote interrupt-sequence
1558 Allow the user to select one of ^C, a BREAK signal or BREAK-g
1559 as the sequence to the remote target in order to interrupt the execution.
1560 Ctrl-C is a default. Some system prefers BREAK which is high level of
1561 serial line for some certain time. Linux kernel prefers BREAK-g, a.k.a
1562 Magic SysRq g. It is BREAK signal and character 'g'.
1564 set remote interrupt-on-connect [on | off]
1565 show remote interrupt-on-connect
1566 When interrupt-on-connect is ON, gdb sends interrupt-sequence to
1567 remote target when gdb connects to it. This is needed when you debug
1570 set remotebreak [on | off]
1572 Deprecated. Use "set/show remote interrupt-sequence" instead.
1574 tvariable $NAME [ = EXP ]
1575 Create or modify a trace state variable.
1578 List trace state variables and their values.
1580 delete tvariable $NAME ...
1581 Delete one or more trace state variables.
1584 Evaluate the given expressions without collecting anything into the
1585 trace buffer. (Valid in tracepoint actions only.)
1587 ftrace FN / FILE:LINE / *ADDR
1588 Define a fast tracepoint at the given function, line, or address.
1590 * New expression syntax
1592 GDB now parses the 0b prefix of binary numbers the same way as GCC does.
1593 GDB now parses 0b101010 identically with 42.
1597 set follow-exec-mode new|same
1598 show follow-exec-mode
1599 Control whether GDB reuses the same inferior across an exec call or
1600 creates a new one. This is useful to be able to restart the old
1601 executable after the inferior having done an exec call.
1603 set default-collect EXPR, ...
1604 show default-collect
1605 Define a list of expressions to be collected at each tracepoint.
1606 This is a useful way to ensure essential items are not overlooked,
1607 such as registers or a critical global variable.
1609 set disconnected-tracing
1610 show disconnected-tracing
1611 If set to 1, the target is instructed to continue tracing if it
1612 loses its connection to GDB. If 0, the target is to stop tracing
1615 set circular-trace-buffer
1616 show circular-trace-buffer
1617 If set to on, the target is instructed to use a circular trace buffer
1618 and discard the oldest trace frames instead of stopping the trace due
1619 to a full trace buffer. If set to off, the trace stops when the buffer
1620 fills up. Some targets may not support this.
1622 set script-extension off|soft|strict
1623 show script-extension
1624 If set to "off", the debugger does not perform any script language
1625 recognition, and all sourced files are assumed to be GDB scripts.
1626 If set to "soft" (the default), files are sourced according to
1627 filename extension, falling back to GDB scripts if the first
1629 If set to "strict", files are sourced according to filename extension.
1631 set ada trust-PAD-over-XVS on|off
1632 show ada trust-PAD-over-XVS
1633 If off, activate a workaround against a bug in the debugging information
1634 generated by the compiler for PAD types (see gcc/exp_dbug.ads in
1635 the GCC sources for more information about the GNAT encoding and
1636 PAD types in particular). It is always safe to set this option to
1637 off, but this introduces a slight performance penalty. The default
1640 * Python API Improvements
1642 ** GDB provides the new class gdb.LazyString. This is useful in
1643 some pretty-printing cases. The new method gdb.Value.lazy_string
1644 provides a simple way to create objects of this type.
1646 ** The fields returned by gdb.Type.fields now have an
1647 `is_base_class' attribute.
1649 ** The new method gdb.Type.range returns the range of an array type.
1651 ** The new method gdb.parse_and_eval can be used to parse and
1652 evaluate an expression.
1654 * New remote packets
1657 Define a trace state variable.
1660 Get the current value of a trace state variable.
1663 Set desired tracing behavior upon disconnection.
1666 Set the trace buffer to be linear or circular.
1669 Get data about the tracepoints currently in use.
1673 Process record now works correctly with hardware watchpoints.
1675 Multiple bug fixes have been made to the mips-irix port, making it
1676 much more reliable. In particular:
1677 - Debugging threaded applications is now possible again. Previously,
1678 GDB would hang while starting the program, or while waiting for
1679 the program to stop at a breakpoint.
1680 - Attaching to a running process no longer hangs.
1681 - An error occurring while loading a core file has been fixed.
1682 - Changing the value of the PC register now works again. This fixes
1683 problems observed when using the "jump" command, or when calling
1684 a function from GDB, or even when assigning a new value to $pc.
1685 - With the "finish" and "return" commands, the return value for functions
1686 returning a small array is now correctly printed.
1687 - It is now possible to break on shared library code which gets executed
1688 during a shared library init phase (code executed while executing
1689 their .init section). Previously, the breakpoint would have no effect.
1690 - GDB is now able to backtrace through the signal handler for
1691 non-threaded programs.
1693 PIE (Position Independent Executable) programs debugging is now supported.
1694 This includes debugging execution of PIC (Position Independent Code) shared
1695 libraries although for that, it should be possible to run such libraries as an
1698 *** Changes in GDB 7.0
1700 * GDB now has an interface for JIT compilation. Applications that
1701 dynamically generate code can create symbol files in memory and register
1702 them with GDB. For users, the feature should work transparently, and
1703 for JIT developers, the interface is documented in the GDB manual in the
1704 "JIT Compilation Interface" chapter.
1706 * Tracepoints may now be conditional. The syntax is as for
1707 breakpoints; either an "if" clause appended to the "trace" command,
1708 or the "condition" command is available. GDB sends the condition to
1709 the target for evaluation using the same bytecode format as is used
1710 for tracepoint actions.
1712 * The disassemble command now supports: an optional /r modifier, print the
1713 raw instructions in hex as well as in symbolic form, and an optional /m
1714 modifier to print mixed source+assembly.
1716 * Process record and replay
1718 In a architecture environment that supports ``process record and
1719 replay'', ``process record and replay'' target can record a log of
1720 the process execution, and replay it with both forward and reverse
1723 * Reverse debugging: GDB now has new commands reverse-continue, reverse-
1724 step, reverse-next, reverse-finish, reverse-stepi, reverse-nexti, and
1725 set execution-direction {forward|reverse}, for targets that support
1728 * GDB now supports hardware watchpoints on MIPS/Linux systems. This
1729 feature is available with a native GDB running on kernel version
1732 * GDB now has support for multi-byte and wide character sets on the
1733 target. Strings whose character type is wchar_t, char16_t, or
1734 char32_t are now correctly printed. GDB supports wide- and unicode-
1735 literals in C, that is, L'x', L"string", u'x', u"string", U'x', and
1736 U"string" syntax. And, GDB allows the "%ls" and "%lc" formats in
1737 `printf'. This feature requires iconv to work properly; if your
1738 system does not have a working iconv, GDB can use GNU libiconv. See
1739 the installation instructions for more information.
1741 * GDB now supports automatic retrieval of shared library files from
1742 remote targets. To use this feature, specify a system root that begins
1743 with the `remote:' prefix, either via the `set sysroot' command or via
1744 the `--with-sysroot' configure-time option.
1746 * "info sharedlibrary" now takes an optional regex of libraries to show,
1747 and it now reports if a shared library has no debugging information.
1749 * Commands `set debug-file-directory', `set solib-search-path' and `set args'
1750 now complete on file names.
1752 * When completing in expressions, gdb will attempt to limit
1753 completions to allowable structure or union fields, where appropriate.
1754 For instance, consider:
1756 # struct example { int f1; double f2; };
1757 # struct example variable;
1760 If the user types TAB at the end of this command line, the available
1761 completions will be "f1" and "f2".
1763 * Inlined functions are now supported. They show up in backtraces, and
1764 the "step", "next", and "finish" commands handle them automatically.
1766 * GDB now supports the token-splicing (##) and stringification (#)
1767 operators when expanding macros. It also supports variable-arity
1770 * GDB now supports inspecting extra signal information, exported by
1771 the new $_siginfo convenience variable. The feature is currently
1772 implemented on linux ARM, i386 and amd64.
1774 * GDB can now display the VFP floating point registers and NEON vector
1775 registers on ARM targets. Both ARM GNU/Linux native GDB and gdbserver
1776 can provide these registers (requires Linux 2.6.30 or later). Remote
1777 and simulator targets may also provide them.
1779 * New remote packets
1782 Search memory for a sequence of bytes.
1785 Turn off `+'/`-' protocol acknowledgments to permit more efficient
1786 operation over reliable transport links. Use of this packet is
1787 controlled by the `set remote noack-packet' command.
1790 Kill the process with the specified process ID. Use this in preference
1791 to `k' when multiprocess protocol extensions are supported.
1794 Obtains additional operating system information
1798 Read or write additional signal information.
1800 * Removed remote protocol undocumented extension
1802 An undocumented extension to the remote protocol's `S' stop reply
1803 packet that permited the stub to pass a process id was removed.
1804 Remote servers should use the `T' stop reply packet instead.
1806 * GDB now supports multiple function calling conventions according to the
1807 DWARF-2 DW_AT_calling_convention function attribute.
1809 * The SH target utilizes the aforementioned change to distinguish between gcc
1810 and Renesas calling convention. It also adds the new CLI commands
1811 `set/show sh calling-convention'.
1813 * GDB can now read compressed debug sections, as produced by GNU gold
1814 with the --compress-debug-sections=zlib flag.
1816 * 64-bit core files are now supported on AIX.
1818 * Thread switching is now supported on Tru64.
1820 * Watchpoints can now be set on unreadable memory locations, e.g. addresses
1821 which will be allocated using malloc later in program execution.
1823 * The qXfer:libraries:read remote procotol packet now allows passing a
1824 list of section offsets.
1826 * On GNU/Linux, GDB can now attach to stopped processes. Several race
1827 conditions handling signals delivered during attach or thread creation
1828 have also been fixed.
1830 * GDB now supports the use of DWARF boolean types for Ada's type Boolean.
1831 From the user's standpoint, all unqualified instances of True and False
1832 are treated as the standard definitions, regardless of context.
1834 * GDB now parses C++ symbol and type names more flexibly. For
1837 template<typename T> class C { };
1840 GDB will now correctly handle all of:
1842 ptype C<char const *>
1843 ptype C<char const*>
1844 ptype C<const char *>
1845 ptype C<const char*>
1847 * New features in the GDB remote stub, gdbserver
1849 - The "--wrapper" command-line argument tells gdbserver to use a
1850 wrapper program to launch programs for debugging.
1852 - On PowerPC and S/390 targets, it is now possible to use a single
1853 gdbserver executable to debug both 32-bit and 64-bit programs.
1854 (This requires gdbserver itself to be built as a 64-bit executable.)
1856 - gdbserver uses the new noack protocol mode for TCP connections to
1857 reduce communications latency, if also supported and enabled in GDB.
1859 - Support for the sparc64-linux-gnu target is now included in
1862 - The amd64-linux build of gdbserver now supports debugging both
1863 32-bit and 64-bit programs.
1865 - The i386-linux, amd64-linux, and i386-win32 builds of gdbserver
1866 now support hardware watchpoints, and will use them automatically
1871 GDB now has support for scripting using Python. Whether this is
1872 available is determined at configure time.
1874 New GDB commands can now be written in Python.
1876 * Ada tasking support
1878 Ada tasks can now be inspected in GDB. The following commands have
1882 Print the list of Ada tasks.
1884 Print detailed information about task number N.
1886 Print the task number of the current task.
1888 Switch the context of debugging to task number N.
1890 * Support for user-defined prefixed commands. The "define" command can
1891 add new commands to existing prefixes, e.g. "target".
1893 * Multi-inferior, multi-process debugging.
1895 GDB now has generalized support for multi-inferior debugging. See
1896 "Debugging Multiple Inferiors" in the manual for more information.
1897 Although availability still depends on target support, the command
1898 set is more uniform now. The GNU/Linux specific multi-forks support
1899 has been migrated to this new framework. This implied some user
1900 visible changes; see "New commands" and also "Removed commands"
1903 * Target descriptions can now describe the target OS ABI. See the
1904 "Target Description Format" section in the user manual for more
1907 * Target descriptions can now describe "compatible" architectures
1908 to indicate that the target can execute applications for a different
1909 architecture in addition to those for the main target architecture.
1910 See the "Target Description Format" section in the user manual for
1913 * Multi-architecture debugging.
1915 GDB now includes general supports for debugging applications on
1916 hybrid systems that use more than one single processor architecture
1917 at the same time. Each such hybrid architecture still requires
1918 specific support to be added. The only hybrid architecture supported
1919 in this version of GDB is the Cell Broadband Engine.
1921 * GDB now supports integrated debugging of Cell/B.E. applications that
1922 use both the PPU and SPU architectures. To enable support for hybrid
1923 Cell/B.E. debugging, you need to configure GDB to support both the
1924 powerpc-linux or powerpc64-linux and the spu-elf targets, using the
1925 --enable-targets configure option.
1927 * Non-stop mode debugging.
1929 For some targets, GDB now supports an optional mode of operation in
1930 which you can examine stopped threads while other threads continue
1931 to execute freely. This is referred to as non-stop mode, with the
1932 old mode referred to as all-stop mode. See the "Non-Stop Mode"
1933 section in the user manual for more information.
1935 To be able to support remote non-stop debugging, a remote stub needs
1936 to implement the non-stop mode remote protocol extensions, as
1937 described in the "Remote Non-Stop" section of the user manual. The
1938 GDB remote stub, gdbserver, has been adjusted to support these
1939 extensions on linux targets.
1941 * New commands (for set/show, see "New options" below)
1943 catch syscall [NAME(S) | NUMBER(S)]
1944 Catch system calls. Arguments, which should be names of system
1945 calls or their numbers, mean catch only those syscalls. Without
1946 arguments, every syscall will be caught. When the inferior issues
1947 any of the specified syscalls, GDB will stop and announce the system
1948 call, both when it is called and when its call returns. This
1949 feature is currently available with a native GDB running on the
1950 Linux Kernel, under the following architectures: x86, x86_64,
1951 PowerPC and PowerPC64.
1953 find [/size-char] [/max-count] start-address, end-address|+search-space-size,
1955 Search memory for a sequence of bytes.
1957 maint set python print-stack
1958 maint show python print-stack
1959 Show a stack trace when an error is encountered in a Python script.
1962 Invoke CODE by passing it to the Python interpreter.
1967 These allow macros to be defined, undefined, and listed
1971 Show operating system information about processes.
1974 List the inferiors currently under GDB's control.
1977 Switch focus to inferior number NUM.
1980 Detach from inferior number NUM.
1983 Kill inferior number NUM.
1987 set spu stop-on-load
1988 show spu stop-on-load
1989 Control whether to stop for new SPE threads during Cell/B.E. debugging.
1991 set spu auto-flush-cache
1992 show spu auto-flush-cache
1993 Control whether to automatically flush the software-managed cache
1994 during Cell/B.E. debugging.
1996 set sh calling-convention
1997 show sh calling-convention
1998 Control the calling convention used when calling SH target functions.
2001 show debug timestamp
2002 Control display of timestamps with GDB debugging output.
2004 set disassemble-next-line
2005 show disassemble-next-line
2006 Control display of disassembled source lines or instructions when
2009 set remote noack-packet
2010 show remote noack-packet
2011 Set/show the use of remote protocol QStartNoAckMode packet. See above
2012 under "New remote packets."
2014 set remote query-attached-packet
2015 show remote query-attached-packet
2016 Control use of remote protocol `qAttached' (query-attached) packet.
2018 set remote read-siginfo-object
2019 show remote read-siginfo-object
2020 Control use of remote protocol `qXfer:siginfo:read' (read-siginfo-object)
2023 set remote write-siginfo-object
2024 show remote write-siginfo-object
2025 Control use of remote protocol `qXfer:siginfo:write' (write-siginfo-object)
2028 set remote reverse-continue
2029 show remote reverse-continue
2030 Control use of remote protocol 'bc' (reverse-continue) packet.
2032 set remote reverse-step
2033 show remote reverse-step
2034 Control use of remote protocol 'bs' (reverse-step) packet.
2036 set displaced-stepping
2037 show displaced-stepping
2038 Control displaced stepping mode. Displaced stepping is a way to
2039 single-step over breakpoints without removing them from the debuggee.
2040 Also known as "out-of-line single-stepping".
2043 show debug displaced
2044 Control display of debugging info for displaced stepping.
2046 maint set internal-error
2047 maint show internal-error
2048 Control what GDB does when an internal error is detected.
2050 maint set internal-warning
2051 maint show internal-warning
2052 Control what GDB does when an internal warning is detected.
2057 Use a wrapper program to launch programs for debugging.
2059 set multiple-symbols (all|ask|cancel)
2060 show multiple-symbols
2061 The value of this variable can be changed to adjust the debugger behavior
2062 when an expression or a breakpoint location contains an ambiguous symbol
2063 name (an overloaded function name, for instance).
2065 set breakpoint always-inserted
2066 show breakpoint always-inserted
2067 Keep breakpoints always inserted in the target, as opposed to inserting
2068 them when resuming the target, and removing them when the target stops.
2069 This option can improve debugger performance on slow remote targets.
2071 set arm fallback-mode (arm|thumb|auto)
2072 show arm fallback-mode
2073 set arm force-mode (arm|thumb|auto)
2075 These commands control how ARM GDB determines whether instructions
2076 are ARM or Thumb. The default for both settings is auto, which uses
2077 the current CPSR value for instructions without symbols; previous
2078 versions of GDB behaved as if "set arm fallback-mode arm".
2080 set disable-randomization
2081 show disable-randomization
2082 Standalone programs run with the virtual address space randomization enabled
2083 by default on some platforms. This option keeps the addresses stable across
2084 multiple debugging sessions.
2088 Control whether other threads are stopped or not when some thread hits
2093 Requests that asynchronous execution is enabled in the target, if available.
2094 In this case, it's possible to resume target in the background, and interact
2095 with GDB while the target is running. "show target-async" displays the
2096 current state of asynchronous execution of the target.
2098 set target-wide-charset
2099 show target-wide-charset
2100 The target-wide-charset is the name of the character set that GDB
2101 uses when printing characters whose type is wchar_t.
2103 set tcp auto-retry (on|off)
2105 set tcp connect-timeout
2106 show tcp connect-timeout
2107 These commands allow GDB to retry failed TCP connections to a remote stub
2108 with a specified timeout period; this is useful if the stub is launched
2109 in parallel with GDB but may not be ready to accept connections immediately.
2111 set libthread-db-search-path
2112 show libthread-db-search-path
2113 Control list of directories which GDB will search for appropriate
2116 set schedule-multiple (on|off)
2117 show schedule-multiple
2118 Allow GDB to resume all threads of all processes or only threads of
2119 the current process.
2123 Use more aggressive caching for accesses to the stack. This improves
2124 performance of remote debugging (particularly backtraces) without
2125 affecting correctness.
2127 set interactive-mode (on|off|auto)
2128 show interactive-mode
2129 Control whether GDB runs in interactive mode (on) or not (off).
2130 When in interactive mode, GDB waits for the user to answer all
2131 queries. Otherwise, GDB does not wait and assumes the default
2132 answer. When set to auto (the default), GDB determines which
2133 mode to use based on the stdin settings.
2138 For program forks, this is replaced by the new more generic `info
2139 inferiors' command. To list checkpoints, you can still use the
2140 `info checkpoints' command, which was an alias for the `info forks'
2144 Replaced by the new `inferior' command. To switch between
2145 checkpoints, you can still use the `restart' command, which was an
2146 alias for the `fork' command.
2149 This is removed, since some targets don't have a notion of
2150 processes. To switch between processes, you can still use the
2151 `inferior' command using GDB's own inferior number.
2154 For program forks, this is replaced by the new more generic `kill
2155 inferior' command. To delete a checkpoint, you can still use the
2156 `delete checkpoint' command, which was an alias for the `delete
2160 For program forks, this is replaced by the new more generic `detach
2161 inferior' command. To detach a checkpoint, you can still use the
2162 `detach checkpoint' command, which was an alias for the `detach
2165 * New native configurations
2167 x86/x86_64 Darwin i[34567]86-*-darwin*
2169 x86_64 MinGW x86_64-*-mingw*
2173 Lattice Mico32 lm32-*
2174 x86 DICOS i[34567]86-*-dicos*
2175 x86_64 DICOS x86_64-*-dicos*
2178 * The GDB remote stub, gdbserver, now supports x86 Windows CE
2179 (mingw32ce) debugging.
2185 These commands were actually not implemented on any target.
2187 *** Changes in GDB 6.8
2189 * New native configurations
2191 NetBSD/hppa hppa*-*netbsd*
2192 Xtensa GNU/Linux xtensa*-*-linux*
2196 NetBSD/hppa hppa*-*-netbsd*
2197 Xtensa GNU/Lunux xtensa*-*-linux*
2199 * Change in command line behavior -- corefiles vs. process ids.
2201 When the '-p NUMBER' or '--pid NUMBER' options are used, and
2202 attaching to process NUMBER fails, GDB no longer attempts to open a
2203 core file named NUMBER. Attaching to a program using the -c option
2204 is no longer supported. Instead, use the '-p' or '--pid' options.
2206 * GDB can now be built as a native debugger for debugging Windows x86
2207 (mingw32) Portable Executable (PE) programs.
2209 * Pending breakpoints no longer change their number when their address
2212 * GDB now supports breakpoints with multiple locations,
2213 including breakpoints on C++ constructors, inside C++ templates,
2214 and in inlined functions.
2216 * GDB's ability to debug optimized code has been improved. GDB more
2217 accurately identifies function bodies and lexical blocks that occupy
2218 more than one contiguous range of addresses.
2220 * Target descriptions can now describe registers for PowerPC.
2222 * The GDB remote stub, gdbserver, now supports the AltiVec and SPE
2223 registers on PowerPC targets.
2225 * The GDB remote stub, gdbserver, now supports thread debugging on GNU/Linux
2226 targets even when the libthread_db library is not available.
2228 * The GDB remote stub, gdbserver, now supports the new file transfer
2229 commands (remote put, remote get, and remote delete).
2231 * The GDB remote stub, gdbserver, now supports run and attach in
2232 extended-remote mode.
2234 * hppa*64*-*-hpux11* target broken
2235 The debugger is unable to start a program and fails with the following
2236 error: "Error trying to get information about dynamic linker".
2237 The gdb-6.7 release is also affected.
2239 * GDB now supports the --enable-targets= configure option to allow
2240 building a single GDB executable that supports multiple remote
2241 target architectures.
2243 * GDB now supports debugging C and C++ programs which use the
2244 Decimal Floating Point extension. In addition, the PowerPC target
2245 now has a set of pseudo-registers to inspect decimal float values
2246 stored in two consecutive float registers.
2248 * The -break-insert MI command can optionally create pending
2251 * Improved support for debugging Ada
2252 Many improvements to the Ada language support have been made. These
2254 - Better support for Ada2005 interface types
2255 - Improved handling of arrays and slices in general
2256 - Better support for Taft-amendment types
2257 - The '{type} ADDRESS' expression is now allowed on the left hand-side
2259 - Improved command completion in Ada
2262 * GDB on GNU/Linux and HP/UX can now debug through "exec" of a new
2267 set print frame-arguments (all|scalars|none)
2268 show print frame-arguments
2269 The value of this variable can be changed to control which argument
2270 values should be printed by the debugger when displaying a frame.
2275 Transfer files to and from a remote target, and delete remote files.
2282 Transfer files to and from a remote target, and delete remote files.
2284 * New remote packets
2291 Open, close, read, write, and delete files on the remote system.
2294 Attach to an existing process on the remote system, in extended-remote
2298 Run a new process on the remote system, in extended-remote mode.
2300 *** Changes in GDB 6.7
2302 * Resolved 101 resource leaks, null pointer dereferences, etc. in gdb,
2303 bfd, libiberty and opcodes, as revealed by static analysis donated by
2304 Coverity, Inc. (http://scan.coverity.com).
2306 * When looking up multiply-defined global symbols, GDB will now prefer the
2307 symbol definition in the current shared library if it was built using the
2308 -Bsymbolic linker option.
2310 * When the Text User Interface (TUI) is not configured, GDB will now
2311 recognize the -tui command-line option and print a message that the TUI
2314 * The GDB remote stub, gdbserver, now has lower overhead for high
2315 frequency signals (e.g. SIGALRM) via the QPassSignals packet.
2317 * GDB for MIPS targets now autodetects whether a remote target provides
2318 32-bit or 64-bit register values.
2320 * Support for C++ member pointers has been improved.
2322 * GDB now understands XML target descriptions, which specify the
2323 target's overall architecture. GDB can read a description from
2324 a local file or over the remote serial protocol.
2326 * Vectors of single-byte data use a new integer type which is not
2327 automatically displayed as character or string data.
2329 * The /s format now works with the print command. It displays
2330 arrays of single-byte integers and pointers to single-byte integers
2333 * Target descriptions can now describe target-specific registers,
2334 for architectures which have implemented the support (currently
2335 only ARM, M68K, and MIPS).
2337 * GDB and the GDB remote stub, gdbserver, now support the XScale
2340 * The GDB remote stub, gdbserver, has been updated to support
2341 ARM Windows CE (mingw32ce) debugging, and GDB Windows CE support
2342 has been rewritten to use the standard GDB remote protocol.
2344 * GDB can now step into C++ functions which are called through thunks.
2346 * GDB for the Cell/B.E. SPU now supports overlay debugging.
2348 * The GDB remote protocol "qOffsets" packet can now honor ELF segment
2349 layout. It also supports a TextSeg= and DataSeg= response when only
2350 segment base addresses (rather than offsets) are available.
2352 * The /i format now outputs any trailing branch delay slot instructions
2353 immediately following the last instruction within the count specified.
2355 * The GDB remote protocol "T" stop reply packet now supports a
2356 "library" response. Combined with the new "qXfer:libraries:read"
2357 packet, this response allows GDB to debug shared libraries on targets
2358 where the operating system manages the list of loaded libraries (e.g.
2359 Windows and SymbianOS).
2361 * The GDB remote stub, gdbserver, now supports dynamic link libraries
2362 (DLLs) on Windows and Windows CE targets.
2364 * GDB now supports a faster verification that a .debug file matches its binary
2365 according to its build-id signature, if the signature is present.
2371 Enable or disable hardware flow control (RTS/CTS) on the serial port
2372 when debugging using remote targets.
2374 set mem inaccessible-by-default
2375 show mem inaccessible-by-default
2376 If the target supplies a memory map, for instance via the remote
2377 protocol's "qXfer:memory-map:read" packet, setting this variable
2378 prevents GDB from accessing memory outside the memory map. This
2379 is useful for targets with memory mapped registers or which react
2380 badly to accesses of unmapped address space.
2382 set breakpoint auto-hw
2383 show breakpoint auto-hw
2384 If the target supplies a memory map, for instance via the remote
2385 protocol's "qXfer:memory-map:read" packet, setting this variable
2386 lets GDB use hardware breakpoints automatically for memory regions
2387 where it can not use software breakpoints. This covers both the
2388 "break" command and internal breakpoints used for other commands
2389 including "next" and "finish".
2392 catch exception unhandled
2393 Stop the program execution when Ada exceptions are raised.
2396 Stop the program execution when an Ada assertion failed.
2400 Set an alternate system root for target files. This is a more
2401 general version of "set solib-absolute-prefix", which is now
2402 an alias to "set sysroot".
2405 Provide extended SPU facility status information. This set of
2406 commands is available only when debugging the Cell/B.E. SPU
2409 * New native configurations
2411 OpenBSD/sh sh*-*openbsd*
2414 unset tdesc filename
2416 Use the specified local file as an XML target description, and do
2417 not query the target for its built-in description.
2421 OpenBSD/sh sh*-*-openbsd*
2422 MIPS64 GNU/Linux (gdbserver) mips64-linux-gnu
2423 Toshiba Media Processor mep-elf
2425 * New remote packets
2428 Ignore the specified signals; pass them directly to the debugged program
2429 without stopping other threads or reporting them to GDB.
2431 qXfer:features:read:
2432 Read an XML target description from the target, which describes its
2437 Read or write contents of an spufs file on the target system. These
2438 packets are available only on the Cell/B.E. SPU architecture.
2440 qXfer:libraries:read:
2441 Report the loaded shared libraries. Combined with new "T" packet
2442 response, this packet allows GDB to debug shared libraries on
2443 targets where the operating system manages the list of loaded
2444 libraries (e.g. Windows and SymbianOS).
2448 Support for these obsolete configurations has been removed.
2456 i[34567]86-*-lynxos*
2457 i[34567]86-*-netware*
2458 i[34567]86-*-sco3.2v5*
2459 i[34567]86-*-sco3.2v4*
2461 i[34567]86-*-sysv4.2*
2464 i[34567]86-*-unixware2*
2465 i[34567]86-*-unixware*
2474 * Other removed features
2481 Various m68k-only ROM monitors.
2488 Various Renesas ROM monitors and debugging interfaces for SH and
2493 Support for a Macraigor serial interface to on-chip debugging.
2494 GDB does not directly support the newer parallel or USB
2499 A debug information format. The predecessor to DWARF 2 and
2500 DWARF 3, which are still supported.
2502 Support for the HP aCC compiler on HP-UX/PA-RISC
2504 SOM-encapsulated symbolic debugging information, automatic
2505 invocation of pxdb, and the aCC custom C++ ABI. This does not
2506 affect HP-UX for Itanium or GCC for HP-UX/PA-RISC. Code compiled
2507 with aCC can still be debugged on an assembly level.
2509 MIPS ".pdr" sections
2511 A MIPS-specific format used to describe stack frame layout
2512 in debugging information.
2516 GDB could work with an older version of Guile to debug
2517 the interpreter and Scheme programs running in it.
2519 set mips stack-arg-size
2520 set mips saved-gpreg-size
2522 Use "set mips abi" to control parameter passing for MIPS.
2524 *** Changes in GDB 6.6
2529 Cell Broadband Engine SPU spu-elf
2531 * GDB can now be configured as a cross-debugger targeting native Windows
2532 (mingw32) or Cygwin. It can communicate with a remote debugging stub
2533 running on a Windows system over TCP/IP to debug Windows programs.
2535 * The GDB remote stub, gdbserver, has been updated to support Windows and
2536 Cygwin debugging. Both single-threaded and multi-threaded programs are
2539 * The "set trust-readonly-sections" command works again. This command was
2540 broken in GDB 6.3, 6.4, and 6.5.
2542 * The "load" command now supports writing to flash memory, if the remote
2543 stub provides the required support.
2545 * Support for GNU/Linux Thread Local Storage (TLS, per-thread variables) no
2546 longer requires symbolic debug information (e.g. DWARF-2).
2551 unset substitute-path
2552 show substitute-path
2553 Manage a list of substitution rules that GDB uses to rewrite the name
2554 of the directories where the sources are located. This can be useful
2555 for instance when the sources were moved to a different location
2556 between compilation and debugging.
2560 Print each CLI command as it is executed. Each command is prefixed with
2561 a number of `+' symbols representing the nesting depth.
2562 The source command now has a `-v' option to enable the same feature.
2566 The ARM Demon monitor support (RDP protocol, "target rdp").
2568 Kernel Object Display, an embedded debugging feature which only worked with
2569 an obsolete version of Cisco IOS.
2571 The 'set download-write-size' and 'show download-write-size' commands.
2573 * New remote packets
2576 Tell a stub about GDB client features, and request remote target features.
2577 The first feature implemented is PacketSize, which allows the target to
2578 specify the size of packets it can handle - to minimize the number of
2579 packets required and improve performance when connected to a remote
2583 Fetch an OS auxilliary vector from the remote stub. This packet is a
2584 more efficient replacement for qPart:auxv:read.
2586 qXfer:memory-map:read:
2587 Fetch a memory map from the remote stub, including information about
2588 RAM, ROM, and flash memory devices.
2593 Erase and program a flash memory device.
2595 * Removed remote packets
2598 This packet has been replaced by qXfer:auxv:read. Only GDB 6.4 and 6.5
2599 used it, and only gdbserver implemented it.
2601 *** Changes in GDB 6.5
2605 Renesas M32C/M16C m32c-elf
2607 Morpho Technologies ms1 ms1-elf
2611 init-if-undefined Initialize a convenience variable, but
2612 only if it doesn't already have a value.
2614 The following commands are presently only implemented for native GNU/Linux:
2616 checkpoint Save a snapshot of the program state.
2618 restart <n> Return the program state to a
2619 previously saved state.
2621 info checkpoints List currently saved checkpoints.
2623 delete-checkpoint <n> Delete a previously saved checkpoint.
2625 set|show detach-on-fork Tell gdb whether to detach from a newly
2626 forked process, or to keep debugging it.
2628 info forks List forks of the user program that
2629 are available to be debugged.
2631 fork <n> Switch to debugging one of several
2632 forks of the user program that are
2633 available to be debugged.
2635 delete-fork <n> Delete a fork from the list of forks
2636 that are available to be debugged (and
2637 kill the forked process).
2639 detach-fork <n> Delete a fork from the list of forks
2640 that are available to be debugged (and
2641 allow the process to continue).
2645 Morpho Technologies ms2 ms1-elf
2647 * Improved Windows host support
2649 GDB now builds as a cross debugger hosted on i686-mingw32, including
2650 native console support, and remote communications using either
2651 network sockets or serial ports.
2653 * Improved Modula-2 language support
2655 GDB can now print most types in the Modula-2 syntax. This includes:
2656 basic types, set types, record types, enumerated types, range types,
2657 pointer types and ARRAY types. Procedure var parameters are correctly
2658 printed and hexadecimal addresses and character constants are also
2659 written in the Modula-2 syntax. Best results can be obtained by using
2660 GNU Modula-2 together with the -gdwarf-2 command line option.
2664 The ARM rdi-share module.
2666 The Netware NLM debug server.
2668 *** Changes in GDB 6.4
2670 * New native configurations
2672 OpenBSD/arm arm*-*-openbsd*
2673 OpenBSD/mips64 mips64-*-openbsd*
2677 Morpho Technologies ms1 ms1-elf
2679 * New command line options
2681 --batch-silent As for --batch, but totally silent.
2682 --return-child-result The debugger will exist with the same value
2683 the child (debugged) program exited with.
2684 --eval-command COMMAND, -ex COMMAND
2685 Execute a single GDB CLI command. This may be
2686 specified multiple times and in conjunction
2687 with the --command (-x) option.
2689 * Deprecated commands removed
2691 The following commands, that were deprecated in 2000, have been
2695 set|show arm disassembly-flavor set|show arm disassembler
2696 othernames set arm disassembler
2697 set|show remotedebug set|show debug remote
2698 set|show archdebug set|show debug arch
2699 set|show eventdebug set|show debug event
2702 * New BSD user-level threads support
2704 It is now possible to debug programs using the user-level threads
2705 library on OpenBSD and FreeBSD. Currently supported (target)
2708 FreeBSD/amd64 x86_64-*-freebsd*
2709 FreeBSD/i386 i386-*-freebsd*
2710 OpenBSD/i386 i386-*-openbsd*
2712 Note that the new kernel threads libraries introduced in FreeBSD 5.x
2713 are not yet supported.
2715 * New support for Matsushita MN10300 w/sim added
2716 (Work in progress). mn10300-elf.
2718 * REMOVED configurations and files
2720 VxWorks and the XDR protocol *-*-vxworks
2721 Motorola MCORE mcore-*-*
2722 National Semiconductor NS32000 ns32k-*-*
2724 * New "set print array-indexes" command
2726 After turning this setting "on", GDB prints the index of each element
2727 when displaying arrays. The default is "off" to preserve the previous
2730 * VAX floating point support
2732 GDB now supports the not-quite-ieee VAX F and D floating point formats.
2734 * User-defined command support
2736 In addition to using $arg0..$arg9 for argument passing, it is now possible
2737 to use $argc to determine now many arguments have been passed. See the
2738 section on user-defined commands in the user manual for more information.
2740 *** Changes in GDB 6.3:
2742 * New command line option
2744 GDB now accepts -l followed by a number to set the timeout for remote
2747 * GDB works with GCC -feliminate-dwarf2-dups
2749 GDB now supports a more compact representation of DWARF-2 debug
2750 information using DW_FORM_ref_addr references. These are produced
2751 by GCC with the option -feliminate-dwarf2-dups and also by some
2752 proprietary compilers. With GCC, you must use GCC 3.3.4 or later
2753 to use -feliminate-dwarf2-dups.
2755 * Internationalization
2757 When supported by the host system, GDB will be built with
2758 internationalization (libintl). The task of marking up the sources is
2759 continued, we're looking forward to our first translation.
2763 Initial support for debugging programs compiled with the GNAT
2764 implementation of the Ada programming language has been integrated
2765 into GDB. In this release, support is limited to expression evaluation.
2767 * New native configurations
2769 GNU/Linux/m32r m32r-*-linux-gnu
2773 GDB's remote protocol now includes support for the 'p' packet. This
2774 packet is used to fetch individual registers from a remote inferior.
2776 * END-OF-LIFE registers[] compatibility module
2778 GDB's internal register infrastructure has been completely rewritten.
2779 The new infrastructure making possible the implementation of key new
2780 features including 32x64 (e.g., 64-bit amd64 GDB debugging a 32-bit
2783 GDB 6.3 will be the last release to include the the registers[]
2784 compatibility module that allowed out-of-date configurations to
2785 continue to work. This change directly impacts the following
2795 powerpc bdm protocol
2797 Unless there is activity to revive these configurations, they will be
2798 made OBSOLETE in GDB 6.4, and REMOVED from GDB 6.5.
2800 * OBSOLETE configurations and files
2802 Configurations that have been declared obsolete in this release have
2803 been commented out. Unless there is activity to revive these
2804 configurations, the next release of GDB will have their sources
2805 permanently REMOVED.
2814 *** Changes in GDB 6.2.1:
2816 * MIPS `break main; run' gave an heuristic-fence-post warning
2818 When attempting to run even a simple program, a warning about
2819 heuristic-fence-post being hit would be reported. This problem has
2822 * MIPS IRIX 'long double' crashed GDB
2824 When examining a long double variable, GDB would get a segmentation
2825 fault. The crash has been fixed (but GDB 6.2 cannot correctly examine
2826 IRIX long double values).
2830 A bug in the VAX stack code was causing problems with the "next"
2831 command. This problem has been fixed.
2833 *** Changes in GDB 6.2:
2835 * Fix for ``many threads''
2837 On GNU/Linux systems that use the NPTL threads library, a program
2838 rapidly creating and deleting threads would confuse GDB leading to the
2841 ptrace: No such process.
2842 thread_db_get_info: cannot get thread info: generic error
2844 This problem has been fixed.
2846 * "-async" and "-noasync" options removed.
2848 Support for the broken "-noasync" option has been removed (it caused
2851 * New ``start'' command.
2853 This command runs the program until the begining of the main procedure.
2855 * New BSD Kernel Data Access Library (libkvm) interface
2857 Using ``target kvm'' it is now possible to debug kernel core dumps and
2858 live kernel memory images on various FreeBSD, NetBSD and OpenBSD
2859 platforms. Currently supported (native-only) configurations are:
2861 FreeBSD/amd64 x86_64-*-freebsd*
2862 FreeBSD/i386 i?86-*-freebsd*
2863 NetBSD/i386 i?86-*-netbsd*
2864 NetBSD/m68k m68*-*-netbsd*
2865 NetBSD/sparc sparc-*-netbsd*
2866 OpenBSD/amd64 x86_64-*-openbsd*
2867 OpenBSD/i386 i?86-*-openbsd*
2868 OpenBSD/m68k m68*-openbsd*
2869 OpenBSD/sparc sparc-*-openbsd*
2871 * Signal trampoline code overhauled
2873 Many generic problems with GDB's signal handling code have been fixed.
2874 These include: backtraces through non-contiguous stacks; recognition
2875 of sa_sigaction signal trampolines; backtrace from a NULL pointer
2876 call; backtrace through a signal trampoline; step into and out of
2877 signal handlers; and single-stepping in the signal trampoline.
2879 Please note that kernel bugs are a limiting factor here. These
2880 features have been shown to work on an s390 GNU/Linux system that
2881 include a 2.6.8-rc1 kernel. Ref PR breakpoints/1702.
2883 * Cygwin support for DWARF 2 added.
2885 * New native configurations
2887 GNU/Linux/hppa hppa*-*-linux*
2888 OpenBSD/hppa hppa*-*-openbsd*
2889 OpenBSD/m68k m68*-*-openbsd*
2890 OpenBSD/m88k m88*-*-openbsd*
2891 OpenBSD/powerpc powerpc-*-openbsd*
2892 NetBSD/vax vax-*-netbsd*
2893 OpenBSD/vax vax-*-openbsd*
2895 * END-OF-LIFE frame compatibility module
2897 GDB's internal frame infrastructure has been completely rewritten.
2898 The new infrastructure making it possible to support key new features
2899 including DWARF 2 Call Frame Information. To aid in the task of
2900 migrating old configurations to this new infrastructure, a
2901 compatibility module, that allowed old configurations to continue to
2902 work, was also included.
2904 GDB 6.2 will be the last release to include this frame compatibility
2905 module. This change directly impacts the following configurations:
2915 Unless there is activity to revive these configurations, they will be
2916 made OBSOLETE in GDB 6.3, and REMOVED from GDB 6.4.
2918 * REMOVED configurations and files
2920 Sun 3, running SunOS 3 m68*-*-sunos3*
2921 Sun 3, running SunOS 4 m68*-*-sunos4*
2922 Sun 2, running SunOS 3 m68000-*-sunos3*
2923 Sun 2, running SunOS 4 m68000-*-sunos4*
2924 Motorola 680x0 running LynxOS m68*-*-lynxos*
2925 AT&T 3b1/Unix pc m68*-att-*
2926 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
2927 decstation mips-dec-* mips-little-*
2928 riscos mips-*-riscos* mips-*-sysv*
2929 sonymips mips-sony-*
2930 sysv mips*-*-sysv4* (IRIX 5/6 not included)
2932 *** Changes in GDB 6.1.1:
2934 * TUI (Text-mode User Interface) built-in (also included in GDB 6.1)
2936 The TUI (Text-mode User Interface) is now built as part of a default
2937 GDB configuration. It is enabled by either selecting the TUI with the
2938 command line option "-i=tui" or by running the separate "gdbtui"
2939 program. For more information on the TUI, see the manual "Debugging
2942 * Pending breakpoint support (also included in GDB 6.1)
2944 Support has been added to allow you to specify breakpoints in shared
2945 libraries that have not yet been loaded. If a breakpoint location
2946 cannot be found, and the "breakpoint pending" option is set to auto,
2947 GDB queries you if you wish to make the breakpoint pending on a future
2948 shared-library load. If and when GDB resolves the breakpoint symbol,
2949 the pending breakpoint is removed as one or more regular breakpoints
2952 Pending breakpoints are very useful for GCJ Java debugging.
2954 * Fixed ISO-C build problems
2956 The files bfd/elf-bfd.h, gdb/dictionary.c and gdb/types.c contained
2957 non ISO-C code that stopped them being built using a more strict ISO-C
2958 compiler (e.g., IBM's C compiler).
2960 * Fixed build problem on IRIX 5
2962 Due to header problems with <sys/proc.h>, the file gdb/proc-api.c
2963 wasn't able to compile compile on an IRIX 5 system.
2965 * Added execute permission to gdb/gdbserver/configure
2967 The shell script gdb/testsuite/gdb.stabs/configure lacked execute
2968 permission. This bug would cause configure to fail on a number of
2969 systems (Solaris, IRIX). Ref: server/519.
2971 * Fixed build problem on hpux2.0w-hp-hpux11.00 using the HP ANSI C compiler
2973 Older HPUX ANSI C compilers did not accept variable array sizes. somsolib.c
2974 has been updated to use constant array sizes.
2976 * Fixed a panic in the DWARF Call Frame Info code on Solaris 2.7
2978 GCC 3.3.2, on Solaris 2.7, includes the DW_EH_PE_funcrel encoding in
2979 its generated DWARF Call Frame Info. This encoding was causing GDB to
2980 panic, that panic has been fixed. Ref: gdb/1628.
2982 * Fixed a problem when examining parameters in shared library code.
2984 When examining parameters in optimized shared library code generated
2985 by a mainline GCC, GDB would incorrectly report ``Variable "..." is
2986 not available''. GDB now correctly displays the variable's value.
2988 *** Changes in GDB 6.1:
2990 * Removed --with-mmalloc
2992 Support for the mmalloc memory manager has been removed, as it
2993 conflicted with the internal gdb byte cache.
2995 * Changes in AMD64 configurations
2997 The AMD64 target now includes the %cs and %ss registers. As a result
2998 the AMD64 remote protocol has changed; this affects the floating-point
2999 and SSE registers. If you rely on those registers for your debugging,
3000 you should upgrade gdbserver on the remote side.
3002 * Revised SPARC target
3004 The SPARC target has been completely revised, incorporating the
3005 FreeBSD/sparc64 support that was added for GDB 6.0. As a result
3006 support for LynxOS and SunOS 4 has been dropped. Calling functions
3007 from within GDB on operating systems with a non-executable stack
3008 (Solaris, OpenBSD) now works.
3012 GDB has a new C++ demangler which does a better job on the mangled
3013 names generated by current versions of g++. It also runs faster, so
3014 with this and other changes gdb should now start faster on large C++
3017 * DWARF 2 Location Expressions
3019 GDB support for location expressions has been extended to support function
3020 arguments and frame bases. Older versions of GDB could crash when they
3023 * C++ nested types and namespaces
3025 GDB's support for nested types and namespaces in C++ has been
3026 improved, especially if you use the DWARF 2 debugging format. (This
3027 is the default for recent versions of GCC on most platforms.)
3028 Specifically, if you have a class "Inner" defined within a class or
3029 namespace "Outer", then GDB realizes that the class's name is
3030 "Outer::Inner", not simply "Inner". This should greatly reduce the
3031 frequency of complaints about not finding RTTI symbols. In addition,
3032 if you are stopped at inside of a function defined within a namespace,
3033 GDB modifies its name lookup accordingly.
3035 * New native configurations
3037 NetBSD/amd64 x86_64-*-netbsd*
3038 OpenBSD/amd64 x86_64-*-openbsd*
3039 OpenBSD/alpha alpha*-*-openbsd*
3040 OpenBSD/sparc sparc-*-openbsd*
3041 OpenBSD/sparc64 sparc64-*-openbsd*
3043 * New debugging protocols
3045 M32R with SDI protocol m32r-*-elf*
3047 * "set prompt-escape-char" command deleted.
3049 The command "set prompt-escape-char" has been deleted. This command,
3050 and its very obscure effet on GDB's prompt, was never documented,
3051 tested, nor mentioned in the NEWS file.
3053 * OBSOLETE configurations and files
3055 Configurations that have been declared obsolete in this release have
3056 been commented out. Unless there is activity to revive these
3057 configurations, the next release of GDB will have their sources
3058 permanently REMOVED.
3060 Sun 3, running SunOS 3 m68*-*-sunos3*
3061 Sun 3, running SunOS 4 m68*-*-sunos4*
3062 Sun 2, running SunOS 3 m68000-*-sunos3*
3063 Sun 2, running SunOS 4 m68000-*-sunos4*
3064 Motorola 680x0 running LynxOS m68*-*-lynxos*
3065 AT&T 3b1/Unix pc m68*-att-*
3066 Bull DPX2 (68k, System V release 3) m68*-bull-sysv*
3067 decstation mips-dec-* mips-little-*
3068 riscos mips-*-riscos* mips-*-sysv*
3069 sonymips mips-sony-*
3070 sysv mips*-*-sysv4* (IRIX 5/6 not included)
3072 * REMOVED configurations and files
3074 SGI Irix-4.x mips-sgi-irix4 or iris4
3075 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
3076 Z8000 simulator z8k-zilog-none or z8ksim
3077 Matsushita MN10200 w/simulator mn10200-*-*
3078 H8/500 simulator h8500-hitachi-hms or h8500hms
3079 HP/PA running BSD hppa*-*-bsd*
3080 HP/PA running OSF/1 hppa*-*-osf*
3081 HP/PA Pro target hppa*-*-pro*
3082 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3083 386BSD i[3456]86-*-bsd*
3084 Sequent family i[3456]86-sequent-sysv4*
3085 i[3456]86-sequent-sysv*
3086 i[3456]86-sequent-bsd*
3087 SPARC running LynxOS sparc-*-lynxos*
3088 SPARC running SunOS 4 sparc-*-sunos4*
3089 Tsqware Sparclet sparclet-*-*
3090 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3092 *** Changes in GDB 6.0:
3096 Support for debugging the Objective-C programming language has been
3097 integrated into GDB.
3099 * New backtrace mechanism (includes DWARF 2 Call Frame Information).
3101 DWARF 2's Call Frame Information makes available compiler generated
3102 information that more exactly describes the program's run-time stack.
3103 By using this information, GDB is able to provide more robust stack
3106 The i386, amd64 (nee, x86-64), Alpha, m68hc11, ia64, and m32r targets
3107 have been updated to use a new backtrace mechanism which includes
3108 DWARF 2 CFI support.
3112 GDB's remote protocol has been extended to include support for hosted
3113 file I/O (where the remote target uses GDB's file system). See GDB's
3114 remote protocol documentation for details.
3116 * All targets using the new architecture framework.
3118 All of GDB's targets have been updated to use the new internal
3119 architecture framework. The way is now open for future GDB releases
3120 to include cross-architecture native debugging support (i386 on amd64,
3123 * GNU/Linux's Thread Local Storage (TLS)
3125 GDB now includes support for for the GNU/Linux implementation of
3126 per-thread variables.
3128 * GNU/Linux's Native POSIX Thread Library (NPTL)
3130 GDB's thread code has been updated to work with either the new
3131 GNU/Linux NPTL thread library or the older "LinuxThreads" library.
3133 * Separate debug info.
3135 GDB, in conjunction with BINUTILS, now supports a mechanism for
3136 automatically loading debug information from a separate file. Instead
3137 of shipping full debug and non-debug versions of system libraries,
3138 system integrators can now instead ship just the stripped libraries
3139 and optional debug files.
3141 * DWARF 2 Location Expressions
3143 DWARF 2 Location Expressions allow the compiler to more completely
3144 describe the location of variables (even in optimized code) to the
3147 GDB now includes preliminary support for location expressions (support
3148 for DW_OP_piece is still missing).
3152 A number of long standing bugs that caused GDB to die while starting a
3153 Java application have been fixed. GDB's Java support is now
3154 considered "useable".
3156 * GNU/Linux support for fork, vfork, and exec.
3158 The "catch fork", "catch exec", "catch vfork", and "set follow-fork-mode"
3159 commands are now implemented for GNU/Linux. They require a 2.5.x or later
3162 * GDB supports logging output to a file
3164 There are two new commands, "set logging" and "show logging", which can be
3165 used to capture GDB's output to a file.
3167 * The meaning of "detach" has changed for gdbserver
3169 The "detach" command will now resume the application, as documented. To
3170 disconnect from gdbserver and leave it stopped, use the new "disconnect"
3173 * d10v, m68hc11 `regs' command deprecated
3175 The `info registers' command has been updated so that it displays the
3176 registers using a format identical to the old `regs' command.
3180 A new command, "maint set profile on/off", has been added. This command can
3181 be used to enable or disable profiling while running GDB, to profile a
3182 session or a set of commands. In addition there is a new configure switch,
3183 "--enable-profiling", which will cause GDB to be compiled with profiling
3184 data, for more informative profiling results.
3186 * Default MI syntax changed to "mi2".
3188 The default MI (machine interface) syntax, enabled by the command line
3189 option "-i=mi", has been changed to "mi2". The previous MI syntax,
3190 "mi1", can be enabled by specifying the option "-i=mi1".
3192 Support for the original "mi0" syntax (included in GDB 5.0) has been
3195 Fix for gdb/192: removed extraneous space when displaying frame level.
3196 Fix for gdb/672: update changelist is now output in mi list format.
3197 Fix for gdb/702: a -var-assign that updates the value now shows up
3198 in a subsequent -var-update.
3200 * New native configurations.
3202 FreeBSD/amd64 x86_64-*-freebsd*
3204 * Multi-arched targets.
3206 HP/PA HPUX11 hppa*-*-hpux*
3207 Renesas M32R/D w/simulator m32r-*-elf*
3209 * OBSOLETE configurations and files
3211 Configurations that have been declared obsolete in this release have
3212 been commented out. Unless there is activity to revive these
3213 configurations, the next release of GDB will have their sources
3214 permanently REMOVED.
3216 Z8000 simulator z8k-zilog-none or z8ksim
3217 Matsushita MN10200 w/simulator mn10200-*-*
3218 H8/500 simulator h8500-hitachi-hms or h8500hms
3219 HP/PA running BSD hppa*-*-bsd*
3220 HP/PA running OSF/1 hppa*-*-osf*
3221 HP/PA Pro target hppa*-*-pro*
3222 PMAX (MIPS) running Mach 3.0 mips*-*-mach3*
3223 Sequent family i[3456]86-sequent-sysv4*
3224 i[3456]86-sequent-sysv*
3225 i[3456]86-sequent-bsd*
3226 Tsqware Sparclet sparclet-*-*
3227 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
3229 * REMOVED configurations and files
3232 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3233 IBM AIX PS/2 i[3456]86-*-aix
3234 i386 running Mach 3.0 i[3456]86-*-mach3*
3235 i386 running Mach i[3456]86-*-mach*
3236 i386 running OSF/1 i[3456]86-*osf1mk*
3237 HP/Apollo 68k Family m68*-apollo*-sysv*,
3239 m68*-hp-bsd*, m68*-hp-hpux*
3240 Argonaut Risc Chip (ARC) arc-*-*
3241 Mitsubishi D30V d30v-*-*
3242 Fujitsu FR30 fr30-*-elf*
3243 OS/9000 i[34]86-*-os9k
3244 I960 with MON960 i960-*-coff
3246 * MIPS $fp behavior changed
3248 The convenience variable $fp, for the MIPS, now consistently returns
3249 the address of the current frame's base. Previously, depending on the
3250 context, $fp could refer to either $sp or the current frame's base
3251 address. See ``8.10 Registers'' in the manual ``Debugging with GDB:
3252 The GNU Source-Level Debugger''.
3254 *** Changes in GDB 5.3:
3256 * GNU/Linux shared library multi-threaded performance improved.
3258 When debugging a multi-threaded application on GNU/Linux, GDB now uses
3259 `/proc', in preference to `ptrace' for memory reads. This may result
3260 in an improvement in the start-up time of multi-threaded, shared
3261 library applications when run under GDB. One GDB user writes: ``loads
3262 shared libs like mad''.
3264 * ``gdbserver'' now supports multi-threaded applications on some targets
3266 Support for debugging multi-threaded applications which use
3267 the GNU/Linux LinuxThreads package has been added for
3268 arm*-*-linux*-gnu*, i[3456]86-*-linux*-gnu*, mips*-*-linux*-gnu*,
3269 powerpc*-*-linux*-gnu*, and sh*-*-linux*-gnu*.
3271 * GDB now supports C/C++ preprocessor macros.
3273 GDB now expands preprocessor macro invocations in C/C++ expressions,
3274 and provides various commands for showing macro definitions and how
3277 The new command `macro expand EXPRESSION' expands any macro
3278 invocations in expression, and shows the result.
3280 The new command `show macro MACRO-NAME' shows the definition of the
3281 macro named MACRO-NAME, and where it was defined.
3283 Most compilers don't include information about macros in the debugging
3284 information by default. In GCC 3.1, for example, you need to compile
3285 your program with the options `-gdwarf-2 -g3'. If the macro
3286 information is present in the executable, GDB will read it.
3288 * Multi-arched targets.
3290 DEC Alpha (partial) alpha*-*-*
3291 DEC VAX (partial) vax-*-*
3293 National Semiconductor NS32000 (partial) ns32k-*-*
3294 Motorola 68000 (partial) m68k-*-*
3295 Motorola MCORE mcore-*-*
3299 Fujitsu FRV architecture added by Red Hat frv*-*-*
3302 * New native configurations
3304 Alpha NetBSD alpha*-*-netbsd*
3305 SH NetBSD sh*-*-netbsdelf*
3306 MIPS NetBSD mips*-*-netbsd*
3307 UltraSPARC NetBSD sparc64-*-netbsd*
3309 * OBSOLETE configurations and files
3311 Configurations that have been declared obsolete in this release have
3312 been commented out. Unless there is activity to revive these
3313 configurations, the next release of GDB will have their sources
3314 permanently REMOVED.
3316 Mitsubishi D30V d30v-*-*
3317 OS/9000 i[34]86-*-os9k
3318 IBM AIX PS/2 i[3456]86-*-aix
3319 Fujitsu FR30 fr30-*-elf*
3320 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
3321 Argonaut Risc Chip (ARC) arc-*-*
3322 i386 running Mach 3.0 i[3456]86-*-mach3*
3323 i386 running Mach i[3456]86-*-mach*
3324 i386 running OSF/1 i[3456]86-*osf1mk*
3325 HP/Apollo 68k Family m68*-apollo*-sysv*,
3327 m68*-hp-bsd*, m68*-hp-hpux*
3328 I960 with MON960 i960-*-coff
3330 * OBSOLETE languages
3332 CHILL, a Pascal like language used by telecommunications companies.
3334 * REMOVED configurations and files
3336 AMD 29k family via UDI a29k-amd-udi, udi29k
3337 A29K VxWorks a29k-*-vxworks
3338 AMD 29000 embedded, using EBMON a29k-none-none
3339 AMD 29000 embedded with COFF a29k-none-coff
3340 AMD 29000 embedded with a.out a29k-none-aout
3342 testsuite/gdb.hp/gdb.threads-hp/ directory
3344 * New command "set max-user-call-depth <nnn>"
3346 This command allows the user to limit the call depth of user-defined
3347 commands. The default is 1024.
3349 * Changes in FreeBSD/i386 native debugging.
3351 Support for the "generate-core-file" has been added.
3353 * New commands "dump", "append", and "restore".
3355 These commands allow data to be copied from target memory
3356 to a bfd-format or binary file (dump and append), and back
3357 from a file into memory (restore).
3359 * Improved "next/step" support on multi-processor Alpha Tru64.
3361 The previous single-step mechanism could cause unpredictable problems,
3362 including the random appearance of SIGSEGV or SIGTRAP signals. The use
3363 of a software single-step mechanism prevents this.
3365 *** Changes in GDB 5.2.1:
3373 gdb/182: gdb/323: gdb/237: On alpha, gdb was reporting:
3374 mdebugread.c:2443: gdb-internal-error: sect_index_data not initialized
3375 Fix, by Joel Brobecker imported from mainline.
3377 gdb/439: gdb/291: On some ELF object files, gdb was reporting:
3378 dwarf2read.c:1072: gdb-internal-error: sect_index_text not initialize
3379 Fix, by Fred Fish, imported from mainline.
3381 Dwarf2 .debug_frame & .eh_frame handler improved in many ways.
3382 Surprisingly enough, it works now.
3383 By Michal Ludvig, imported from mainline.
3385 i386 hardware watchpoint support:
3386 avoid misses on second run for some targets.
3387 By Pierre Muller, imported from mainline.
3389 *** Changes in GDB 5.2:
3391 * New command "set trust-readonly-sections on[off]".
3393 This command is a hint that tells gdb that read-only sections
3394 really are read-only (ie. that their contents will not change).
3395 In this mode, gdb will go to the object file rather than the
3396 target to read memory from read-only sections (such as ".text").
3397 This can be a significant performance improvement on some
3398 (notably embedded) targets.
3400 * New command "generate-core-file" (or "gcore").
3402 This new gdb command allows the user to drop a core file of the child
3403 process state at any time. So far it's been implemented only for
3404 GNU/Linux and Solaris, but should be relatively easily ported to other
3405 hosts. Argument is core file name (defaults to core.<pid>).
3407 * New command line option
3409 GDB now accepts --pid or -p followed by a process id.
3411 * Change in command line behavior -- corefiles vs. process ids.
3413 There is a subtle behavior in the way in which GDB handles
3414 command line arguments. The first non-flag argument is always
3415 a program to debug, but the second non-flag argument may either
3416 be a corefile or a process id. Previously, GDB would attempt to
3417 open the second argument as a corefile, and if that failed, would
3418 issue a superfluous error message and then attempt to attach it as
3419 a process. Now, if the second argument begins with a non-digit,
3420 it will be treated as a corefile. If it begins with a digit,
3421 GDB will attempt to attach it as a process, and if no such process
3422 is found, will then attempt to open it as a corefile.
3424 * Changes in ARM configurations.
3426 Multi-arch support is enabled for all ARM configurations. The ARM/NetBSD
3427 configuration is fully multi-arch.
3429 * New native configurations
3431 ARM NetBSD arm*-*-netbsd*
3432 x86 OpenBSD i[3456]86-*-openbsd*
3433 AMD x86-64 running GNU/Linux x86_64-*-linux-*
3434 Sparc64 running FreeBSD sparc64-*-freebsd*
3438 Sanyo XStormy16 xstormy16-elf
3440 * OBSOLETE configurations and files
3442 Configurations that have been declared obsolete in this release have
3443 been commented out. Unless there is activity to revive these
3444 configurations, the next release of GDB will have their sources
3445 permanently REMOVED.
3447 AMD 29k family via UDI a29k-amd-udi, udi29k
3448 A29K VxWorks a29k-*-vxworks
3449 AMD 29000 embedded, using EBMON a29k-none-none
3450 AMD 29000 embedded with COFF a29k-none-coff
3451 AMD 29000 embedded with a.out a29k-none-aout
3453 testsuite/gdb.hp/gdb.threads-hp/ directory
3455 * REMOVED configurations and files
3457 TI TMS320C80 tic80-*-*
3459 PowerPC Solaris powerpcle-*-solaris*
3460 PowerPC Windows NT powerpcle-*-cygwin32
3461 PowerPC Netware powerpc-*-netware*
3462 Harris/CXUX m88k m88*-harris-cxux*
3463 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3464 ns32k-utek-sysv* ns32k-utek-*
3465 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3466 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3467 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3468 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3469 Apple Macintosh (MPW) host and target N/A host, powerpc-*-macos*
3471 * Changes to command line processing
3473 The new `--args' feature can be used to specify command-line arguments
3474 for the inferior from gdb's command line.
3476 * Changes to key bindings
3478 There is a new `operate-and-get-next' function bound to `C-o'.
3480 *** Changes in GDB 5.1.1
3482 Fix compile problem on DJGPP.
3484 Fix a problem with floating-point registers on the i386 being
3487 Fix to stop GDB crashing on .debug_str debug info.
3489 Numerous documentation fixes.
3491 Numerous testsuite fixes.
3493 *** Changes in GDB 5.1:
3495 * New native configurations
3497 Alpha FreeBSD alpha*-*-freebsd*
3498 x86 FreeBSD 3.x and 4.x i[3456]86*-freebsd[34]*
3499 MIPS GNU/Linux mips*-*-linux*
3500 MIPS SGI Irix 6.x mips*-sgi-irix6*
3501 ia64 AIX ia64-*-aix*
3502 s390 and s390x GNU/Linux {s390,s390x}-*-linux*
3506 Motorola 68HC11 and 68HC12 m68hc11-elf
3508 UltraSparc running GNU/Linux sparc64-*-linux*
3510 * OBSOLETE configurations and files
3512 x86 FreeBSD before 2.2 i[3456]86*-freebsd{1,2.[01]}*,
3513 Harris/CXUX m88k m88*-harris-cxux*
3514 Most ns32k hosts and targets ns32k-*-mach3* ns32k-umax-*
3515 ns32k-utek-sysv* ns32k-utek-*
3516 TI TMS320C80 tic80-*-*
3518 Ultracomputer (29K) running Sym1 a29k-nyu-sym1 a29k-*-kern*
3519 PowerPC Solaris powerpcle-*-solaris*
3520 PowerPC Windows NT powerpcle-*-cygwin32
3521 PowerPC Netware powerpc-*-netware*
3522 SunOS 4.0.Xi on i386 i[3456]86-*-sunos*
3523 Sony NEWS (68K) running NEWSOS 3.x m68*-sony-sysv news
3524 ISI Optimum V (3.05) under 4.3bsd. m68*-isi-*
3525 Apple Macintosh (MPW) host N/A
3527 stuff.c (Program to stuff files into a specially prepared space in kdb)
3528 kdb-start.c (Main loop for the standalone kernel debugger)
3530 Configurations that have been declared obsolete in this release have
3531 been commented out. Unless there is activity to revive these
3532 configurations, the next release of GDB will have their sources
3533 permanently REMOVED.
3535 * REMOVED configurations and files
3537 Altos 3068 m68*-altos-*
3538 Convex c1-*-*, c2-*-*
3540 ARM RISCix arm-*-* (as host)
3544 * GDB has been converted to ISO C.
3546 GDB's source code has been converted to ISO C. In particular, the
3547 sources are fully protoized, and rely on standard headers being
3552 * "info symbol" works on platforms which use COFF, ECOFF, XCOFF, and NLM.
3554 * The MI enabled by default.
3556 The new machine oriented interface (MI) introduced in GDB 5.0 has been
3557 revised and enabled by default. Packages which use GDB as a debugging
3558 engine behind a UI or another front end are encouraged to switch to
3559 using the GDB/MI interface, instead of the old annotations interface
3560 which is now deprecated.
3562 * Support for debugging Pascal programs.
3564 GDB now includes support for debugging Pascal programs. The following
3565 main features are supported:
3567 - Pascal-specific data types such as sets;
3569 - automatic recognition of Pascal sources based on file-name
3572 - Pascal-style display of data types, variables, and functions;
3574 - a Pascal expression parser.
3576 However, some important features are not yet supported.
3578 - Pascal string operations are not supported at all;
3580 - there are some problems with boolean types;
3582 - Pascal type hexadecimal constants are not supported
3583 because they conflict with the internal variables format;
3585 - support for Pascal objects and classes is not full yet;
3587 - unlike Pascal, GDB is case-sensitive for symbol names.
3589 * Changes in completion.
3591 Commands such as `shell', `run' and `set args', which pass arguments
3592 to inferior programs, now complete on file names, similar to what
3593 users expect at the shell prompt.
3595 Commands which accept locations, such as `disassemble', `print',
3596 `breakpoint', `until', etc. now complete on filenames as well as
3597 program symbols. Thus, if you type "break foob TAB", and the source
3598 files linked into the programs include `foobar.c', that file name will
3599 be one of the candidates for completion. However, file names are not
3600 considered for completion after you typed a colon that delimits a file
3601 name from a name of a function in that file, as in "break foo.c:bar".
3603 `set demangle-style' completes on available demangling styles.
3605 * New platform-independent commands:
3607 It is now possible to define a post-hook for a command as well as a
3608 hook that runs before the command. For more details, see the
3609 documentation of `hookpost' in the GDB manual.
3611 * Changes in GNU/Linux native debugging.
3613 Support for debugging multi-threaded programs has been completely
3614 revised for all platforms except m68k and sparc. You can now debug as
3615 many threads as your system allows you to have.
3617 Attach/detach is supported for multi-threaded programs.
3619 Support for SSE registers was added for x86. This doesn't work for
3620 multi-threaded programs though.
3622 * Changes in MIPS configurations.
3624 Multi-arch support is enabled for all MIPS configurations.
3626 GDB can now be built as native debugger on SGI Irix 6.x systems for
3627 debugging n32 executables. (Debugging 64-bit executables is not yet
3630 * Unified support for hardware watchpoints in all x86 configurations.
3632 Most (if not all) native x86 configurations support hardware-assisted
3633 breakpoints and watchpoints in a unified manner. This support
3634 implements debug register sharing between watchpoints, which allows to
3635 put a virtually infinite number of watchpoints on the same address,
3636 and also supports watching regions up to 16 bytes with several debug
3639 The new maintenance command `maintenance show-debug-regs' toggles
3640 debugging print-outs in functions that insert, remove, and test
3641 watchpoints and hardware breakpoints.
3643 * Changes in the DJGPP native configuration.
3645 New command ``info dos sysinfo'' displays assorted information about
3646 the CPU, OS, memory, and DPMI server.
3648 New commands ``info dos gdt'', ``info dos ldt'', and ``info dos idt''
3649 display information about segment descriptors stored in GDT, LDT, and
3652 New commands ``info dos pde'' and ``info dos pte'' display entries
3653 from Page Directory and Page Tables (for now works with CWSDPMI only).
3654 New command ``info dos address-pte'' displays the Page Table entry for
3655 a given linear address.
3657 GDB can now pass command lines longer than 126 characters to the
3658 program being debugged (requires an update to the libdbg.a library
3659 which is part of the DJGPP development kit).
3661 DWARF2 debug info is now supported.
3663 It is now possible to `step' and `next' through calls to `longjmp'.
3665 * Changes in documentation.
3667 All GDB documentation was converted to GFDL, the GNU Free
3668 Documentation License.
3670 Tracepoints-related commands are now fully documented in the GDB
3673 TUI, the Text-mode User Interface, is now documented in the manual.
3675 Tracepoints-related commands are now fully documented in the GDB
3678 The "GDB Internals" manual now has an index. It also includes
3679 documentation of `ui_out' functions, GDB coding standards, x86
3680 hardware watchpoints, and memory region attributes.
3682 * GDB's version number moved to ``version.in''
3684 The Makefile variable VERSION has been replaced by the file
3685 ``version.in''. People creating GDB distributions should update the
3686 contents of this file.
3690 GUD support is now a standard part of the EMACS distribution.
3692 *** Changes in GDB 5.0:
3694 * Improved support for debugging FP programs on x86 targets
3696 Unified and much-improved support for debugging floating-point
3697 programs on all x86 targets. In particular, ``info float'' now
3698 displays the FP registers in the same format on all x86 targets, with
3699 greater level of detail.
3701 * Improvements and bugfixes in hardware-assisted watchpoints
3703 It is now possible to watch array elements, struct members, and
3704 bitfields with hardware-assisted watchpoints. Data-read watchpoints
3705 on x86 targets no longer erroneously trigger when the address is
3708 * Improvements in the native DJGPP version of GDB
3710 The distribution now includes all the scripts and auxiliary files
3711 necessary to build the native DJGPP version on MS-DOS/MS-Windows
3712 machines ``out of the box''.
3714 The DJGPP version can now debug programs that use signals. It is
3715 possible to catch signals that happened in the debuggee, deliver
3716 signals to it, interrupt it with Ctrl-C, etc. (Previously, a signal
3717 would kill the program being debugged.) Programs that hook hardware
3718 interrupts (keyboard, timer, etc.) can also be debugged.
3720 It is now possible to debug DJGPP programs that redirect their
3721 standard handles or switch them to raw (as opposed to cooked) mode, or
3722 even close them. The command ``run < foo > bar'' works as expected,
3723 and ``info terminal'' reports useful information about the debuggee's
3724 terminal, including raw/cooked mode, redirection, etc.
3726 The DJGPP version now uses termios functions for console I/O, which
3727 enables debugging graphics programs. Interrupting GDB with Ctrl-C
3730 DOS-style file names with drive letters are now fully supported by
3733 It is now possible to debug DJGPP programs that switch their working
3734 directory. It is also possible to rerun the debuggee any number of
3735 times without restarting GDB; thus, you can use the same setup,
3736 breakpoints, etc. for many debugging sessions.
3738 * New native configurations
3740 ARM GNU/Linux arm*-*-linux*
3741 PowerPC GNU/Linux powerpc-*-linux*
3745 Motorola MCore mcore-*-*
3746 x86 VxWorks i[3456]86-*-vxworks*
3747 PowerPC VxWorks powerpc-*-vxworks*
3748 TI TMS320C80 tic80-*-*
3750 * OBSOLETE configurations
3752 Altos 3068 m68*-altos-*
3753 Convex c1-*-*, c2-*-*
3755 ARM RISCix arm-*-* (as host)
3758 Configurations that have been declared obsolete will be commented out,
3759 but the code will be left in place. If there is no activity to revive
3760 these configurations before the next release of GDB, the sources will
3761 be permanently REMOVED.
3763 * Gould support removed
3765 Support for the Gould PowerNode and NP1 has been removed.
3767 * New features for SVR4
3769 On SVR4 native platforms (such as Solaris), if you attach to a process
3770 without first loading a symbol file, GDB will now attempt to locate and
3771 load symbols from the running process's executable file.
3773 * Many C++ enhancements
3775 C++ support has been greatly improved. Overload resolution now works properly
3776 in almost all cases. RTTI support is on the way.
3778 * Remote targets can connect to a sub-program
3780 A popen(3) style serial-device has been added. This device starts a
3781 sub-process (such as a stand-alone simulator) and then communicates
3782 with that. The sub-program to run is specified using the syntax
3783 ``|<program> <args>'' vis:
3785 (gdb) set remotedebug 1
3786 (gdb) target extended-remote |mn10300-elf-sim program-args
3788 * MIPS 64 remote protocol
3790 A long standing bug in the mips64 remote protocol where by GDB
3791 expected certain 32 bit registers (ex SR) to be transfered as 32
3792 instead of 64 bits has been fixed.
3794 The command ``set remote-mips64-transfers-32bit-regs on'' has been
3795 added to provide backward compatibility with older versions of GDB.
3797 * ``set remotebinarydownload'' replaced by ``set remote X-packet''
3799 The command ``set remotebinarydownload'' command has been replaced by
3800 ``set remote X-packet''. Other commands in ``set remote'' family
3801 include ``set remote P-packet''.
3803 * Breakpoint commands accept ranges.
3805 The breakpoint commands ``enable'', ``disable'', and ``delete'' now
3806 accept a range of breakpoints, e.g. ``5-7''. The tracepoint command
3807 ``tracepoint passcount'' also accepts a range of tracepoints.
3809 * ``apropos'' command added.
3811 The ``apropos'' command searches through command names and
3812 documentation strings, printing out matches, making it much easier to
3813 try to find a command that does what you are looking for.
3817 A new machine oriented interface (MI) has been added to GDB. This
3818 interface is designed for debug environments running GDB as a separate
3819 process. This is part of the long term libGDB project. See the
3820 "GDB/MI" chapter of the GDB manual for further information. It can be
3821 enabled by configuring with:
3823 .../configure --enable-gdbmi
3825 *** Changes in GDB-4.18:
3827 * New native configurations
3829 HP-UX 10.20 hppa*-*-hpux10.20
3830 HP-UX 11.x hppa*-*-hpux11.0*
3831 M68K GNU/Linux m68*-*-linux*
3835 Fujitsu FR30 fr30-*-elf*
3836 Intel StrongARM strongarm-*-*
3837 Mitsubishi D30V d30v-*-*
3839 * OBSOLETE configurations
3841 Gould PowerNode, NP1 np1-*-*, pn-*-*
3843 Configurations that have been declared obsolete will be commented out,
3844 but the code will be left in place. If there is no activity to revive
3845 these configurations before the next release of GDB, the sources will
3846 be permanently REMOVED.
3850 As a compatibility experiment, GDB's source files buildsym.h and
3851 buildsym.c have been converted to pure standard C, no longer
3852 containing any K&R compatibility code. We believe that all systems in
3853 use today either come with a standard C compiler, or have a GCC port
3854 available. If this is not true, please report the affected
3855 configuration to bug-gdb@gnu.org immediately. See the README file for
3856 information about getting a standard C compiler if you don't have one
3861 GDB now uses readline 2.2.
3863 * set extension-language
3865 You can now control the mapping between filename extensions and source
3866 languages by using the `set extension-language' command. For instance,
3867 you can ask GDB to treat .c files as C++ by saying
3868 set extension-language .c c++
3869 The command `info extensions' lists all of the recognized extensions
3870 and their associated languages.
3872 * Setting processor type for PowerPC and RS/6000
3874 When GDB is configured for a powerpc*-*-* or an rs6000*-*-* target,
3875 you can use the `set processor' command to specify what variant of the
3876 PowerPC family you are debugging. The command
3880 sets the PowerPC/RS6000 variant to NAME. GDB knows about the
3881 following PowerPC and RS6000 variants:
3883 ppc-uisa PowerPC UISA - a PPC processor as viewed by user-level code
3884 rs6000 IBM RS6000 ("POWER") architecture, user-level view
3886 403GC IBM PowerPC 403GC
3887 505 Motorola PowerPC 505
3888 860 Motorola PowerPC 860 or 850
3889 601 Motorola PowerPC 601
3890 602 Motorola PowerPC 602
3891 603 Motorola/IBM PowerPC 603 or 603e
3892 604 Motorola PowerPC 604 or 604e
3893 750 Motorola/IBM PowerPC 750 or 750
3895 At the moment, this command just tells GDB what to name the
3896 special-purpose processor registers. Since almost all the affected
3897 registers are inaccessible to user-level programs, this command is
3898 only useful for remote debugging in its present form.
3902 Thanks to a major code donation from Hewlett-Packard, GDB now has much
3903 more extensive support for HP-UX. Added features include shared
3904 library support, kernel threads and hardware watchpoints for 11.00,
3905 support for HP's ANSI C and C++ compilers, and a compatibility mode
3906 for xdb and dbx commands.
3910 HP's donation includes the new concept of catchpoints, which is a
3911 generalization of the old catch command. On HP-UX, it is now possible
3912 to catch exec, fork, and vfork, as well as library loading.
3914 This means that the existing catch command has changed; its first
3915 argument now specifies the type of catch to be set up. See the
3916 output of "help catch" for a list of catchpoint types.
3918 * Debugging across forks
3920 On HP-UX, you can choose which process to debug when a fork() happens
3925 HP has donated a curses-based terminal user interface (TUI). To get
3926 it, build with --enable-tui. Although this can be enabled for any
3927 configuration, at present it only works for native HP debugging.
3929 * GDB remote protocol additions
3931 A new protocol packet 'X' that writes binary data is now available.
3932 Default behavior is to try 'X', then drop back to 'M' if the stub
3933 fails to respond. The settable variable `remotebinarydownload'
3934 allows explicit control over the use of 'X'.
3936 For 64-bit targets, the memory packets ('M' and 'm') can now contain a
3937 full 64-bit address. The command
3939 set remoteaddresssize 32
3941 can be used to revert to the old behaviour. For existing remote stubs
3942 the change should not be noticed, as the additional address information
3945 In order to assist in debugging stubs, you may use the maintenance
3946 command `packet' to send any text string to the stub. For instance,
3948 maint packet heythere
3950 sends the packet "$heythere#<checksum>". Note that it is very easy to
3951 disrupt a debugging session by sending the wrong packet at the wrong
3954 The compare-sections command allows you to compare section data on the
3955 target to what is in the executable file without uploading or
3956 downloading, by comparing CRC checksums.
3958 * Tracing can collect general expressions
3960 You may now collect general expressions at tracepoints. This requires
3961 further additions to the target-side stub; see tracepoint.c and
3962 doc/agentexpr.texi for further details.
3964 * mask-address variable for Mips
3966 For Mips targets, you may control the zeroing of the upper 32 bits of
3967 a 64-bit address by entering `set mask-address on'. This is mainly
3968 of interest to users of embedded R4xxx and R5xxx processors.
3970 * Higher serial baud rates
3972 GDB's serial code now allows you to specify baud rates 57600, 115200,
3973 230400, and 460800 baud. (Note that your host system may not be able
3974 to achieve all of these rates.)
3978 The i960 configuration now includes an initial implementation of a
3979 builtin simulator, contributed by Jim Wilson.
3982 *** Changes in GDB-4.17:
3984 * New native configurations
3986 Alpha GNU/Linux alpha*-*-linux*
3987 Unixware 2.x i[3456]86-unixware2*
3988 Irix 6.x mips*-sgi-irix6*
3989 PowerPC GNU/Linux powerpc-*-linux*
3990 PowerPC Solaris powerpcle-*-solaris*
3991 Sparc GNU/Linux sparc-*-linux*
3992 Motorola sysV68 R3V7.1 m68k-motorola-sysv
3996 Argonaut Risc Chip (ARC) arc-*-*
3997 Hitachi H8/300S h8300*-*-*
3998 Matsushita MN10200 w/simulator mn10200-*-*
3999 Matsushita MN10300 w/simulator mn10300-*-*
4000 MIPS NEC VR4100 mips64*vr4100*{,el}-*-elf*
4001 MIPS NEC VR5000 mips64*vr5000*{,el}-*-elf*
4002 MIPS Toshiba TX39 mips64*tx39*{,el}-*-elf*
4003 Mitsubishi D10V w/simulator d10v-*-*
4004 Mitsubishi M32R/D w/simulator m32r-*-elf*
4005 Tsqware Sparclet sparclet-*-*
4006 NEC V850 w/simulator v850-*-*
4008 * New debugging protocols
4010 ARM with RDI protocol arm*-*-*
4011 M68K with dBUG monitor m68*-*-{aout,coff,elf}
4012 DDB and LSI variants of PMON protocol mips*-*-*
4013 PowerPC with DINK32 monitor powerpc{,le}-*-eabi
4014 PowerPC with SDS protocol powerpc{,le}-*-eabi
4015 Macraigor OCD (Wiggler) devices powerpc{,le}-*-eabi
4019 All configurations can now understand and use the DWARF 2 debugging
4020 format. The choice is automatic, if the symbol file contains DWARF 2
4025 GDB now includes basic Java language support. This support is
4026 only useful with Java compilers that produce native machine code.
4028 * solib-absolute-prefix and solib-search-path
4030 For SunOS and SVR4 shared libraries, you may now set the prefix for
4031 loading absolute shared library symbol files, and the search path for
4032 locating non-absolute shared library symbol files.
4034 * Live range splitting
4036 GDB can now effectively debug code for which GCC has performed live
4037 range splitting as part of its optimization. See gdb/doc/LRS for
4038 more details on the expected format of the stabs information.
4042 GDB's support for the GNU Hurd, including thread debugging, has been
4043 updated to work with current versions of the Hurd.
4047 GDB's ARM target configuration now handles the ARM7T (Thumb) 16-bit
4048 instruction set. ARM GDB automatically detects when Thumb
4049 instructions are in use, and adjusts disassembly and backtracing
4054 GDB's MIPS target configurations now handle the MIP16 16-bit
4059 GDB now includes support for overlays; if an executable has been
4060 linked such that multiple sections are based at the same address, GDB
4061 will decide which section to use for symbolic info. You can choose to
4062 control the decision manually, using overlay commands, or implement
4063 additional target-side support and use "overlay load-target" to bring
4064 in the overlay mapping. Do "help overlay" for more detail.
4068 The command "info symbol <address>" displays information about
4069 the symbol at the specified address.
4073 The standard remote protocol now includes an extension that allows
4074 asynchronous collection and display of trace data. This requires
4075 extensive support in the target-side debugging stub. Tracing mode
4076 includes a new interaction mode in GDB and new commands: see the
4077 file tracepoint.c for more details.
4081 Configurations for embedded MIPS now include a simulator contributed
4082 by Cygnus Solutions. The simulator supports the instruction sets
4083 of most MIPS variants.
4087 Sparc configurations may now include the ERC32 simulator contributed
4088 by the European Space Agency. The simulator is not built into
4089 Sparc targets by default; configure with --enable-sim to include it.
4093 For target configurations that may include multiple variants of a
4094 basic architecture (such as MIPS and SH), you may now set the
4095 architecture explicitly. "set arch" sets, "info arch" lists
4096 the possible architectures.
4098 *** Changes in GDB-4.16:
4100 * New native configurations
4102 Windows 95, x86 Windows NT i[345]86-*-cygwin32
4103 M68K NetBSD m68k-*-netbsd*
4104 PowerPC AIX 4.x powerpc-*-aix*
4105 PowerPC MacOS powerpc-*-macos*
4106 PowerPC Windows NT powerpcle-*-cygwin32
4107 RS/6000 AIX 4.x rs6000-*-aix4*
4111 ARM with RDP protocol arm-*-*
4112 I960 with MON960 i960-*-coff
4113 MIPS VxWorks mips*-*-vxworks*
4114 MIPS VR4300 with PMON mips64*vr4300{,el}-*-elf*
4115 PowerPC with PPCBUG monitor powerpc{,le}-*-eabi*
4117 Matra Sparclet sparclet-*-*
4121 The powerpc-eabi configuration now includes the PSIM simulator,
4122 contributed by Andrew Cagney, with assistance from Mike Meissner.
4123 PSIM is a very elaborate model of the PowerPC, including not only
4124 basic instruction set execution, but also details of execution unit
4125 performance and I/O hardware. See sim/ppc/README for more details.
4129 GDB now works with Solaris 2.5.
4131 * Windows 95/NT native
4133 GDB will now work as a native debugger on Windows 95 and Windows NT.
4134 To build it from source, you must use the "gnu-win32" environment,
4135 which uses a DLL to emulate enough of Unix to run the GNU tools.
4136 Further information, binaries, and sources are available at
4137 ftp.cygnus.com, under pub/gnu-win32.
4139 * dont-repeat command
4141 If a user-defined command includes the command `dont-repeat', then the
4142 command will not be repeated if the user just types return. This is
4143 useful if the command is time-consuming to run, so that accidental
4144 extra keystrokes don't run the same command many times.
4146 * Send break instead of ^C
4148 The standard remote protocol now includes an option to send a break
4149 rather than a ^C to the target in order to interrupt it. By default,
4150 GDB will send ^C; to send a break, set the variable `remotebreak' to 1.
4152 * Remote protocol timeout
4154 The standard remote protocol includes a new variable `remotetimeout'
4155 that allows you to set the number of seconds before GDB gives up trying
4156 to read from the target. The default value is 2.
4158 * Automatic tracking of dynamic object loading (HPUX and Solaris only)
4160 By default GDB will automatically keep track of objects as they are
4161 loaded and unloaded by the dynamic linker. By using the command `set
4162 stop-on-solib-events 1' you can arrange for GDB to stop the inferior
4163 when shared library events occur, thus allowing you to set breakpoints
4164 in shared libraries which are explicitly loaded by the inferior.
4166 Note this feature does not work on hpux8. On hpux9 you must link
4167 /usr/lib/end.o into your program. This feature should work
4168 automatically on hpux10.
4170 * Irix 5.x hardware watchpoint support
4172 Irix 5 configurations now support the use of hardware watchpoints.
4174 * Mips protocol "SYN garbage limit"
4176 When debugging a Mips target using the `target mips' protocol, you
4177 may set the number of characters that GDB will ignore by setting
4178 the `syn-garbage-limit'. A value of -1 means that GDB will ignore
4179 every character. The default value is 1050.
4181 * Recording and replaying remote debug sessions
4183 If you set `remotelogfile' to the name of a file, gdb will write to it
4184 a recording of a remote debug session. This recording may then be
4185 replayed back to gdb using "gdbreplay". See gdbserver/README for
4186 details. This is useful when you have a problem with GDB while doing
4187 remote debugging; you can make a recording of the session and send it
4188 to someone else, who can then recreate the problem.
4190 * Speedups for remote debugging
4192 GDB includes speedups for downloading and stepping MIPS systems using
4193 the IDT monitor, fast downloads to the Hitachi SH E7000 emulator,
4194 and more efficient S-record downloading.
4196 * Memory use reductions and statistics collection
4198 GDB now uses less memory and reports statistics about memory usage.
4199 Try the `maint print statistics' command, for example.
4201 *** Changes in GDB-4.15:
4203 * Psymtabs for XCOFF
4205 The symbol reader for AIX GDB now uses partial symbol tables. This
4206 can greatly improve startup time, especially for large executables.
4208 * Remote targets use caching
4210 Remote targets now use a data cache to speed up communication with the
4211 remote side. The data cache could lead to incorrect results because
4212 it doesn't know about volatile variables, thus making it impossible to
4213 debug targets which use memory mapped I/O devices. `set remotecache
4214 off' turns the the data cache off.
4216 * Remote targets may have threads
4218 The standard remote protocol now includes support for multiple threads
4219 in the target system, using new protocol commands 'H' and 'T'. See
4220 gdb/remote.c for details.
4224 If GDB is configured with `--enable-netrom', then it will include
4225 support for the NetROM ROM emulator from XLNT Designs. The NetROM
4226 acts as though it is a bank of ROM on the target board, but you can
4227 write into it over the network. GDB's support consists only of
4228 support for fast loading into the emulated ROM; to debug, you must use
4229 another protocol, such as standard remote protocol. The usual
4230 sequence is something like
4232 target nrom <netrom-hostname>
4234 target remote <netrom-hostname>:1235
4238 GDB now includes support for the Apple Macintosh, as a host only. It
4239 may be run as either an MPW tool or as a standalone application, and
4240 it can debug through the serial port. All the usual GDB commands are
4241 available, but to the target command, you must supply "serial" as the
4242 device type instead of "/dev/ttyXX". See mpw-README in the main
4243 directory for more information on how to build. The MPW configuration
4244 scripts */mpw-config.in support only a few targets, and only the
4245 mips-idt-ecoff target has been tested.
4249 GDB configuration now uses autoconf. This is not user-visible,
4250 but does simplify configuration and building.
4254 GDB now supports hpux10.
4256 *** Changes in GDB-4.14:
4258 * New native configurations
4260 x86 FreeBSD i[345]86-*-freebsd
4261 x86 NetBSD i[345]86-*-netbsd
4262 NS32k NetBSD ns32k-*-netbsd
4263 Sparc NetBSD sparc-*-netbsd
4267 A29K VxWorks a29k-*-vxworks
4268 HP PA PRO embedded (WinBond W89K & Oki OP50N) hppa*-*-pro*
4269 CPU32 EST-300 emulator m68*-*-est*
4270 PowerPC ELF powerpc-*-elf
4273 * Alpha OSF/1 support for procfs
4275 GDB now supports procfs under OSF/1-2.x and higher, which makes it
4276 possible to attach to running processes. As the mounting of the /proc
4277 filesystem is optional on the Alpha, GDB automatically determines
4278 the availability of /proc during startup. This can lead to problems
4279 if /proc is unmounted after GDB has been started.
4281 * Arguments to user-defined commands
4283 User commands may accept up to 10 arguments separated by whitespace.
4284 Arguments are accessed within the user command via $arg0..$arg9. A
4287 print $arg0 + $arg1 + $arg2
4289 To execute the command use:
4292 Defines the command "adder" which prints the sum of its three arguments.
4293 Note the arguments are text substitutions, so they may reference variables,
4294 use complex expressions, or even perform inferior function calls.
4296 * New `if' and `while' commands
4298 This makes it possible to write more sophisticated user-defined
4299 commands. Both commands take a single argument, which is the
4300 expression to evaluate, and must be followed by the commands to
4301 execute, one per line, if the expression is nonzero, the list being
4302 terminated by the word `end'. The `if' command list may include an
4303 `else' word, which causes the following commands to be executed only
4304 if the expression is zero.
4306 * Fortran source language mode
4308 GDB now includes partial support for Fortran 77. It will recognize
4309 Fortran programs and can evaluate a subset of Fortran expressions, but
4310 variables and functions may not be handled correctly. GDB will work
4311 with G77, but does not yet know much about symbols emitted by other
4314 * Better HPUX support
4316 Most debugging facilities now work on dynamic executables for HPPAs
4317 running hpux9 or later. You can attach to running dynamically linked
4318 processes, but by default the dynamic libraries will be read-only, so
4319 for instance you won't be able to put breakpoints in them. To change
4320 that behavior do the following before running the program:
4326 This will cause the libraries to be mapped private and read-write.
4327 To revert to the normal behavior, do this:
4333 You cannot set breakpoints or examine data in the library until after
4334 the library is loaded if the function/data symbols do not have
4337 GDB can now also read debug symbols produced by the HP C compiler on
4338 HPPAs (sorry, no C++, Fortran or 68k support).
4340 * Target byte order now dynamically selectable
4342 You can choose which byte order to use with a target system, via the
4343 commands "set endian big" and "set endian little", and you can see the
4344 current setting by using "show endian". You can also give the command
4345 "set endian auto", in which case GDB will use the byte order
4346 associated with the executable. Currently, only embedded MIPS
4347 configurations support dynamic selection of target byte order.
4349 * New DOS host serial code
4351 This version uses DPMI interrupts to handle buffered I/O, so you
4352 no longer need to run asynctsr when debugging boards connected to
4355 *** Changes in GDB-4.13:
4357 * New "complete" command
4359 This lists all the possible completions for the rest of the line, if it
4360 were to be given as a command itself. This is intended for use by emacs.
4362 * Trailing space optional in prompt
4364 "set prompt" no longer adds a space for you after the prompt you set. This
4365 allows you to set a prompt which ends in a space or one that does not.
4367 * Breakpoint hit counts
4369 "info break" now displays a count of the number of times the breakpoint
4370 has been hit. This is especially useful in conjunction with "ignore"; you
4371 can ignore a large number of breakpoint hits, look at the breakpoint info
4372 to see how many times the breakpoint was hit, then run again, ignoring one
4373 less than that number, and this will get you quickly to the last hit of
4376 * Ability to stop printing at NULL character
4378 "set print null-stop" will cause GDB to stop printing the characters of
4379 an array when the first NULL is encountered. This is useful when large
4380 arrays actually contain only short strings.
4382 * Shared library breakpoints
4384 In SunOS 4.x, SVR4, and Alpha OSF/1 configurations, you can now set
4385 breakpoints in shared libraries before the executable is run.
4387 * Hardware watchpoints
4389 There is a new hardware breakpoint for the watch command for sparclite
4390 targets. See gdb/sparclite/hw_breakpoint.note.
4392 Hardware watchpoints are also now supported under GNU/Linux.
4396 Annotations have been added. These are for use with graphical interfaces,
4397 and are still experimental. Currently only gdba.el uses these.
4399 * Improved Irix 5 support
4401 GDB now works properly with Irix 5.2.
4403 * Improved HPPA support
4405 GDB now works properly with the latest GCC and GAS.
4407 * New native configurations
4409 Sequent PTX4 i[34]86-sequent-ptx4
4410 HPPA running OSF/1 hppa*-*-osf*
4411 Atari TT running SVR4 m68*-*-sysv4*
4412 RS/6000 LynxOS rs6000-*-lynxos*
4416 OS/9000 i[34]86-*-os9k
4417 MIPS R4000 mips64*{,el}-*-{ecoff,elf}
4420 * Hitachi SH7000 and E7000-PC ICE support
4422 There is now support for communicating with the Hitachi E7000-PC ICE.
4423 This is available automatically when GDB is configured for the SH.
4427 As usual, a variety of small fixes and improvements, both generic
4428 and configuration-specific. See the ChangeLog for more detail.
4430 *** Changes in GDB-4.12:
4432 * Irix 5 is now supported
4436 GDB-4.12 on the HPPA has a number of changes which make it unable
4437 to debug the output from the currently released versions of GCC and
4438 GAS (GCC 2.5.8 and GAS-2.2 or PAGAS-1.36). Until the next major release
4439 of GCC and GAS, versions of these tools designed to work with GDB-4.12
4440 can be retrieved via anonymous ftp from jaguar.cs.utah.edu:/dist.
4443 *** Changes in GDB-4.11:
4445 * User visible changes:
4449 The "set remotedebug" option is now consistent between the mips remote
4450 target, remote targets using the gdb-specific protocol, UDI (AMD's
4451 debug protocol for the 29k) and the 88k bug monitor. It is now an
4452 integer specifying a debug level (normally 0 or 1, but 2 means more
4453 debugging info for the mips target).
4455 * DEC Alpha native support
4457 GDB now works on the DEC Alpha. GCC 2.4.5 does not produce usable
4458 debug info, but GDB works fairly well with the DEC compiler and should
4459 work with a future GCC release. See the README file for a few
4460 Alpha-specific notes.
4462 * Preliminary thread implementation
4464 GDB now has preliminary thread support for both SGI/Irix and LynxOS.
4466 * LynxOS native and target support for 386
4468 This release has been hosted on LynxOS 2.2, and also can be configured
4469 to remotely debug programs running under LynxOS (see gdb/gdbserver/README
4472 * Improvements in C++ mangling/demangling.
4474 This release has much better g++ debugging, specifically in name
4475 mangling/demangling, virtual function calls, print virtual table,
4476 call methods, ...etc.
4478 *** Changes in GDB-4.10:
4480 * User visible changes:
4482 Remote debugging using the GDB-specific (`target remote') protocol now
4483 supports the `load' command. This is only useful if you have some
4484 other way of getting the stub to the target system, and you can put it
4485 somewhere in memory where it won't get clobbered by the download.
4487 Filename completion now works.
4489 When run under emacs mode, the "info line" command now causes the
4490 arrow to point to the line specified. Also, "info line" prints
4491 addresses in symbolic form (as well as hex).
4493 All vxworks based targets now support a user settable option, called
4494 vxworks-timeout. This option represents the number of seconds gdb
4495 should wait for responses to rpc's. You might want to use this if
4496 your vxworks target is, perhaps, a slow software simulator or happens
4497 to be on the far side of a thin network line.
4501 This release contains support for using a DEC alpha as a GDB host for
4502 cross debugging. Native alpha debugging is not supported yet.
4505 *** Changes in GDB-4.9:
4509 This is the first GDB release which is accompanied by a matching testsuite.
4510 The testsuite requires installation of dejagnu, which should be available
4511 via ftp from most sites that carry GNU software.
4515 'Cfront' style demangling has had its name changed to 'ARM' style, to
4516 emphasize that it was written from the specifications in the C++ Annotated
4517 Reference Manual, not necessarily to be compatible with AT&T cfront. Despite
4518 disclaimers, it still generated too much confusion with users attempting to
4519 use gdb with AT&T cfront.
4523 GDB now uses a standard remote interface to a simulator library.
4524 So far, the library contains simulators for the Zilog Z8001/2, the
4525 Hitachi H8/300, H8/500 and Super-H.
4527 * New targets supported
4529 H8/300 simulator h8300-hitachi-hms or h8300hms
4530 H8/500 simulator h8500-hitachi-hms or h8500hms
4531 SH simulator sh-hitachi-hms or sh
4532 Z8000 simulator z8k-zilog-none or z8ksim
4533 IDT MIPS board over serial line mips-idt-ecoff
4535 Cross-debugging to GO32 targets is supported. It requires a custom
4536 version of the i386-stub.c module which is integrated with the
4537 GO32 memory extender.
4539 * New remote protocols
4541 MIPS remote debugging protocol.
4543 * New source languages supported
4545 This version includes preliminary support for Chill, a Pascal like language
4546 used by telecommunications companies. Chill support is also being integrated
4547 into the GNU compiler, but we don't know when it will be publically available.
4550 *** Changes in GDB-4.8:
4552 * HP Precision Architecture supported
4554 GDB now supports HP PA-RISC machines running HPUX. A preliminary
4555 version of this support was available as a set of patches from the
4556 University of Utah. GDB does not support debugging of programs
4557 compiled with the HP compiler, because HP will not document their file
4558 format. Instead, you must use GCC (version 2.3.2 or later) and PA-GAS
4559 (as available from jaguar.cs.utah.edu:/dist/pa-gas.u4.tar.Z).
4561 Many problems in the preliminary version have been fixed.
4563 * Faster and better demangling
4565 We have improved template demangling and fixed numerous bugs in the GNU style
4566 demangler. It can now handle type modifiers such as `static' or `const'. Wide
4567 character types (wchar_t) are now supported. Demangling of each symbol is now
4568 only done once, and is cached when the symbol table for a file is read in.
4569 This results in a small increase in memory usage for C programs, a moderate
4570 increase in memory usage for C++ programs, and a fantastic speedup in
4573 `Cfront' style demangling still doesn't work with AT&T cfront. It was written
4574 from the specifications in the Annotated Reference Manual, which AT&T's
4575 compiler does not actually implement.
4577 * G++ multiple inheritance compiler problem
4579 In the 2.3.2 release of gcc/g++, how the compiler resolves multiple
4580 inheritance lattices was reworked to properly discover ambiguities. We
4581 recently found an example which causes this new algorithm to fail in a
4582 very subtle way, producing bad debug information for those classes.
4583 The file 'gcc.patch' (in this directory) can be applied to gcc to
4584 circumvent the problem. A future GCC release will contain a complete
4587 The previous G++ debug info problem (mentioned below for the gdb-4.7
4588 release) is fixed in gcc version 2.3.2.
4590 * Improved configure script
4592 The `configure' script will now attempt to guess your system type if
4593 you don't supply a host system type. The old scheme of supplying a
4594 host system triplet is preferable over using this. All the magic is
4595 done in the new `config.guess' script. Examine it for details.
4597 We have also brought our configure script much more in line with the FSF's
4598 version. It now supports the --with-xxx options. In particular,
4599 `--with-minimal-bfd' can be used to make the GDB binary image smaller.
4600 The resulting GDB will not be able to read arbitrary object file formats --
4601 only the format ``expected'' to be used on the configured target system.
4602 We hope to make this the default in a future release.
4604 * Documentation improvements
4606 There's new internal documentation on how to modify GDB, and how to
4607 produce clean changes to the code. We implore people to read it
4608 before submitting changes.
4610 The GDB manual uses new, sexy Texinfo conditionals, rather than arcane
4611 M4 macros. The new texinfo.tex is provided in this release. Pre-built
4612 `info' files are also provided. To build `info' files from scratch,
4613 you will need the latest `makeinfo' release, which will be available in
4614 a future texinfo-X.Y release.
4616 *NOTE* The new texinfo.tex can cause old versions of TeX to hang.
4617 We're not sure exactly which versions have this problem, but it has
4618 been seen in 3.0. We highly recommend upgrading to TeX version 3.141
4619 or better. If that isn't possible, there is a patch in
4620 `texinfo/tex3patch' that will modify `texinfo/texinfo.tex' to work
4621 around this problem.
4625 GDB now supports array constants that can be used in expressions typed in by
4626 the user. The syntax is `{element, element, ...}'. Ie: you can now type
4627 `print {1, 2, 3}', and it will build up an array in memory malloc'd in
4630 The new directory `gdb/sparclite' contains a program that demonstrates
4631 how the sparc-stub.c remote stub runs on a Fujitsu SPARClite processor.
4633 * New native hosts supported
4635 HP/PA-RISC under HPUX using GNU tools hppa1.1-hp-hpux
4636 386 CPUs running SCO Unix 3.2v4 i386-unknown-sco3.2v4
4638 * New targets supported
4640 AMD 29k family via UDI a29k-amd-udi or udi29k
4642 * New file formats supported
4644 BFD now supports reading HP/PA-RISC executables (SOM file format?),
4645 HPUX core files, and SCO 3.2v2 core files.
4649 Attaching to processes now works again; thanks for the many bug reports.
4651 We have also stomped on a bunch of core dumps caused by
4652 printf_filtered("%s") problems.
4654 We eliminated a copyright problem on the rpc and ptrace header files
4655 for VxWorks, which was discovered at the last minute during the 4.7
4656 release. You should now be able to build a VxWorks GDB.
4658 You can now interrupt gdb while an attached process is running. This
4659 will cause the attached process to stop, and give control back to GDB.
4661 We fixed problems caused by using too many file descriptors
4662 for reading symbols from object files and libraries. This was
4663 especially a problem for programs that used many (~100) shared
4666 The `step' command now only enters a subroutine if there is line number
4667 information for the subroutine. Otherwise it acts like the `next'
4668 command. Previously, `step' would enter subroutines if there was
4669 any debugging information about the routine. This avoids problems
4670 when using `cc -g1' on MIPS machines.
4672 * Internal improvements
4674 GDB's internal interfaces have been improved to make it easier to support
4675 debugging of multiple languages in the future.
4677 GDB now uses a common structure for symbol information internally.
4678 Minimal symbols (derived from linkage symbols in object files), partial
4679 symbols (from a quick scan of debug information), and full symbols
4680 contain a common subset of information, making it easier to write
4681 shared code that handles any of them.
4683 * New command line options
4685 We now accept --silent as an alias for --quiet.
4689 The memory-mapped-malloc library is now licensed under the GNU Library
4690 General Public License.
4692 *** Changes in GDB-4.7:
4694 * Host/native/target split
4696 GDB has had some major internal surgery to untangle the support for
4697 hosts and remote targets. Now, when you configure GDB for a remote
4698 target, it will no longer load in all of the support for debugging
4699 local programs on the host. When fully completed and tested, this will
4700 ensure that arbitrary host/target combinations are possible.
4702 The primary conceptual shift is to separate the non-portable code in
4703 GDB into three categories. Host specific code is required any time GDB
4704 is compiled on that host, regardless of the target. Target specific
4705 code relates to the peculiarities of the target, but can be compiled on
4706 any host. Native specific code is everything else: it can only be
4707 built when the host and target are the same system. Child process
4708 handling and core file support are two common `native' examples.
4710 GDB's use of /proc for controlling Unix child processes is now cleaner.
4711 It has been split out into a single module under the `target_ops' vector,
4712 plus two native-dependent functions for each system that uses /proc.
4714 * New hosts supported
4716 HP/Apollo 68k (under the BSD domain) m68k-apollo-bsd or apollo68bsd
4717 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4718 386 CPUs running SCO Unix i386-unknown-scosysv322 or i386sco
4720 * New targets supported
4722 Fujitsu SPARClite sparclite-fujitsu-none or sparclite
4723 68030 and CPU32 m68030-*-*, m68332-*-*
4725 * New native hosts supported
4727 386 CPUs running various BSD ports i386-unknown-bsd or 386bsd
4728 (386bsd is not well tested yet)
4729 386 CPUs running SCO Unix i386-unknown-scosysv322 or sco
4731 * New file formats supported
4733 BFD now supports COFF files for the Zilog Z8000 microprocessor. It
4734 supports reading of `a.out.adobe' object files, which are an a.out
4735 format extended with minimal information about multiple sections.
4739 `show copying' is the same as the old `info copying'.
4740 `show warranty' is the same as `info warrantee'.
4741 These were renamed for consistency. The old commands continue to work.
4743 `info handle' is a new alias for `info signals'.
4745 You can now define pre-command hooks, which attach arbitrary command
4746 scripts to any command. The commands in the hook will be executed
4747 prior to the user's command. You can also create a hook which will be
4748 executed whenever the program stops. See gdb.texinfo.
4752 We now deal with Cfront style name mangling, and can even extract type
4753 info from mangled symbols. GDB can automatically figure out which
4754 symbol mangling style your C++ compiler uses.
4756 Calling of methods and virtual functions has been improved as well.
4760 The crash that occured when debugging Sun Ansi-C compiled binaries is
4761 fixed. This was due to mishandling of the extra N_SO stabs output
4764 We also finally got Ultrix 4.2 running in house, and fixed core file
4765 support, with help from a dozen people on the net.
4767 John M. Farrell discovered that the reason that single-stepping was so
4768 slow on all of the Mips based platforms (primarily SGI and DEC) was
4769 that we were trying to demangle and lookup a symbol used for internal
4770 purposes on every instruction that was being stepped through. Changing
4771 the name of that symbol so that it couldn't be mistaken for a C++
4772 mangled symbol sped things up a great deal.
4774 Rich Pixley sped up symbol lookups in general by getting much smarter
4775 about when C++ symbol mangling is necessary. This should make symbol
4776 completion (TAB on the command line) much faster. It's not as fast as
4777 we'd like, but it's significantly faster than gdb-4.6.
4781 A new user controllable variable 'call_scratch_address' can
4782 specify the location of a scratch area to be used when GDB
4783 calls a function in the target. This is necessary because the
4784 usual method of putting the scratch area on the stack does not work
4785 in systems that have separate instruction and data spaces.
4787 We integrated changes to support the 29k UDI (Universal Debugger
4788 Interface), but discovered at the last minute that we didn't have all
4789 of the appropriate copyright paperwork. We are working with AMD to
4790 resolve this, and hope to have it available soon.
4794 We have sped up the remote serial line protocol, especially for targets
4795 with lots of registers. It now supports a new `expedited status' ('T')
4796 message which can be used in place of the existing 'S' status message.
4797 This allows the remote stub to send only the registers that GDB
4798 needs to make a quick decision about single-stepping or conditional
4799 breakpoints, eliminating the need to fetch the entire register set for
4800 each instruction being stepped through.
4802 The GDB remote serial protocol now implements a write-through cache for
4803 registers, only re-reading the registers if the target has run.
4805 There is also a new remote serial stub for SPARC processors. You can
4806 find it in gdb-4.7/gdb/sparc-stub.c. This was written to support the
4807 Fujitsu SPARClite processor, but will run on any stand-alone SPARC
4808 processor with a serial port.
4812 Configure.in files have become much easier to read and modify. A new
4813 `table driven' format makes it more obvious what configurations are
4814 supported, and what files each one uses.
4818 There is a new opcodes library which will eventually contain all of the
4819 disassembly routines and opcode tables. At present, it only contains
4820 Sparc and Z8000 routines. This will allow the assembler, debugger, and
4821 disassembler (binutils/objdump) to share these routines.
4823 The libiberty library is now copylefted under the GNU Library General
4824 Public License. This allows more liberal use, and was done so libg++
4825 can use it. This makes no difference to GDB, since the Library License
4826 grants all the rights from the General Public License.
4830 The file gdb-4.7/gdb/doc/stabs.texinfo is a (relatively) complete
4831 reference to the stabs symbol info used by the debugger. It is (as far
4832 as we know) the only published document on this fascinating topic. We
4833 encourage you to read it, compare it to the stabs information on your
4834 system, and send improvements on the document in general (to
4835 bug-gdb@prep.ai.mit.edu).
4837 And, of course, many bugs have been fixed.
4840 *** Changes in GDB-4.6:
4842 * Better support for C++ function names
4844 GDB now accepts as input the "demangled form" of C++ overloaded function
4845 names and member function names, and can do command completion on such names
4846 (using TAB, TAB-TAB, and ESC-?). The names have to be quoted with a pair of
4847 single quotes. Examples are 'func (int, long)' and 'obj::operator==(obj&)'.
4848 Make use of command completion, it is your friend.
4850 GDB also now accepts a variety of C++ mangled symbol formats. They are
4851 the GNU g++ style, the Cfront (ARM) style, and the Lucid (lcc) style.
4852 You can tell GDB which format to use by doing a 'set demangle-style {gnu,
4853 lucid, cfront, auto}'. 'gnu' is the default. Do a 'set demangle-style foo'
4854 for the list of formats.
4856 * G++ symbol mangling problem
4858 Recent versions of gcc have a bug in how they emit debugging information for
4859 C++ methods (when using dbx-style stabs). The file 'gcc.patch' (in this
4860 directory) can be applied to gcc to fix the problem. Alternatively, if you
4861 can't fix gcc, you can #define GCC_MANGLE_BUG when compling gdb/symtab.c. The
4862 usual symptom is difficulty with setting breakpoints on methods. GDB complains
4863 about the method being non-existent. (We believe that version 2.2.2 of GCC has
4866 * New 'maintenance' command
4868 All of the commands related to hacking GDB internals have been moved out of
4869 the main command set, and now live behind the 'maintenance' command. This
4870 can also be abbreviated as 'mt'. The following changes were made:
4872 dump-me -> maintenance dump-me
4873 info all-breakpoints -> maintenance info breakpoints
4874 printmsyms -> maintenance print msyms
4875 printobjfiles -> maintenance print objfiles
4876 printpsyms -> maintenance print psymbols
4877 printsyms -> maintenance print symbols
4879 The following commands are new:
4881 maintenance demangle Call internal GDB demangler routine to
4882 demangle a C++ link name and prints the result.
4883 maintenance print type Print a type chain for a given symbol
4885 * Change to .gdbinit file processing
4887 We now read the $HOME/.gdbinit file before processing the argv arguments
4888 (e.g. reading symbol files or core files). This allows global parameters to
4889 be set, which will apply during the symbol reading. The ./.gdbinit is still
4890 read after argv processing.
4892 * New hosts supported
4894 Solaris-2.0 !!! sparc-sun-solaris2 or sun4sol2
4896 GNU/Linux support i386-unknown-linux or linux
4898 We are also including code to support the HP/PA running BSD and HPUX. This
4899 is almost guaranteed not to work, as we didn't have time to test or build it
4900 for this release. We are including it so that the more adventurous (or
4901 masochistic) of you can play with it. We also had major problems with the
4902 fact that the compiler that we got from HP doesn't support the -g option.
4905 * New targets supported
4907 Hitachi H8/300 h8300-hitachi-hms or h8300hms
4909 * More smarts about finding #include files
4911 GDB now remembers the compilation directory for all include files, and for
4912 all files from which C is generated (like yacc and lex sources). This
4913 greatly improves GDB's ability to find yacc/lex sources, and include files,
4914 especially if you are debugging your program from a directory different from
4915 the one that contains your sources.
4917 We also fixed a bug which caused difficulty with listing and setting
4918 breakpoints in include files which contain C code. (In the past, you had to
4919 try twice in order to list an include file that you hadn't looked at before.)
4921 * Interesting infernals change
4923 GDB now deals with arbitrary numbers of sections, where the symbols for each
4924 section must be relocated relative to that section's landing place in the
4925 target's address space. This work was needed to support ELF with embedded
4926 stabs used by Solaris-2.0.
4928 * Bug fixes (of course!)
4930 There have been loads of fixes for the following things:
4931 mips, rs6000, 29k/udi, m68k, g++, type handling, elf/dwarf, m88k,
4932 i960, stabs, DOS(GO32), procfs, etc...
4934 See the ChangeLog for details.
4936 *** Changes in GDB-4.5:
4938 * New machines supported (host and target)
4940 IBM RS6000 running AIX rs6000-ibm-aix or rs6000
4942 SGI Irix-4.x mips-sgi-irix4 or iris4
4944 * New malloc package
4946 GDB now uses a new memory manager called mmalloc, based on gmalloc.
4947 Mmalloc is capable of handling mutiple heaps of memory. It is also
4948 capable of saving a heap to a file, and then mapping it back in later.
4949 This can be used to greatly speedup the startup of GDB by using a
4950 pre-parsed symbol table which lives in a mmalloc managed heap. For
4951 more details, please read mmalloc/mmalloc.texi.
4955 The 'info proc' command (SVR4 only) has been enhanced quite a bit. See
4956 'help info proc' for details.
4958 * MIPS ecoff symbol table format
4960 The code that reads MIPS symbol table format is now supported on all hosts.
4961 Thanks to MIPS for releasing the sym.h and symconst.h files to make this
4964 * File name changes for MS-DOS
4966 Many files in the config directories have been renamed to make it easier to
4967 support GDB on MS-DOSe systems (which have very restrictive file name
4968 conventions :-( ). MS-DOSe host support (under DJ Delorie's GO32
4969 environment) is close to working but has some remaining problems. Note
4970 that debugging of DOS programs is not supported, due to limitations
4971 in the ``operating system'', but it can be used to host cross-debugging.
4973 * Cross byte order fixes
4975 Many fixes have been made to support cross debugging of Sparc and MIPS
4976 targets from hosts whose byte order differs.
4978 * New -mapped and -readnow options
4980 If memory-mapped files are available on your system through the 'mmap'
4981 system call, you can use the -mapped option on the `file' or
4982 `symbol-file' commands to cause GDB to write the symbols from your
4983 program into a reusable file. If the program you are debugging is
4984 called `/path/fred', the mapped symbol file will be `./fred.syms'.
4985 Future GDB debugging sessions will notice the presence of this file,
4986 and will quickly map in symbol information from it, rather than reading
4987 the symbol table from the executable program. Using the '-mapped'
4988 option in a GDB `file' or `symbol-file' command has the same effect as
4989 starting GDB with the '-mapped' command-line option.
4991 You can cause GDB to read the entire symbol table immediately by using
4992 the '-readnow' option with any of the commands that load symbol table
4993 information (or on the GDB command line). This makes the command
4994 slower, but makes future operations faster.
4996 The -mapped and -readnow options are typically combined in order to
4997 build a `fred.syms' file that contains complete symbol information.
4998 A simple GDB invocation to do nothing but build a `.syms' file for future
5001 gdb -batch -nx -mapped -readnow programname
5003 The `.syms' file is specific to the host machine on which GDB is run.
5004 It holds an exact image of GDB's internal symbol table. It cannot be
5005 shared across multiple host platforms.
5007 * longjmp() handling
5009 GDB is now capable of stepping and nexting over longjmp(), _longjmp(), and
5010 siglongjmp() without losing control. This feature has not yet been ported to
5011 all systems. It currently works on many 386 platforms, all MIPS-based
5012 platforms (SGI, DECstation, etc), and Sun3/4.
5016 Preliminary work has been put in to support the new Solaris OS from Sun. At
5017 this time, it can control and debug processes, but it is not capable of
5022 As always, many many bug fixes. The major areas were with g++, and mipsread.
5023 People using the MIPS-based platforms should experience fewer mysterious
5024 crashes and trashed symbol tables.
5026 *** Changes in GDB-4.4:
5028 * New machines supported (host and target)
5030 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5032 BSD Reno on Vax vax-dec-bsd
5033 Ultrix on Vax vax-dec-ultrix
5035 * New machines supported (target)
5037 AMD 29000 embedded, using EBMON a29k-none-none
5041 GDB continues to improve its handling of C++. `References' work better.
5042 The demangler has also been improved, and now deals with symbols mangled as
5043 per the Annotated C++ Reference Guide.
5045 GDB also now handles `stabs' symbol information embedded in MIPS
5046 `ecoff' symbol tables. Since the ecoff format was not easily
5047 extensible to handle new languages such as C++, this appeared to be a
5048 good way to put C++ debugging info into MIPS binaries. This option
5049 will be supported in the GNU C compiler, version 2, when it is
5052 * New features for SVR4
5054 GDB now handles SVR4 shared libraries, in the same fashion as SunOS
5055 shared libraries. Debugging dynamically linked programs should present
5056 only minor differences from debugging statically linked programs.
5058 The `info proc' command will print out information about any process
5059 on an SVR4 system (including the one you are debugging). At the moment,
5060 it prints the address mappings of the process.
5062 If you bring up GDB on another SVR4 system, please send mail to
5063 bug-gdb@prep.ai.mit.edu to let us know what changes were reqired (if any).
5065 * Better dynamic linking support in SunOS
5067 Reading symbols from shared libraries which contain debugging symbols
5068 now works properly. However, there remain issues such as automatic
5069 skipping of `transfer vector' code during function calls, which
5070 make it harder to debug code in a shared library, than to debug the
5071 same code linked statically.
5075 GDB is now using the latest `getopt' routines from the FSF. This
5076 version accepts the -- prefix for options with long names. GDB will
5077 continue to accept the old forms (-option and +option) as well.
5078 Various single letter abbreviations for options have been explicity
5079 added to the option table so that they won't get overshadowed in the
5080 future by other options that begin with the same letter.
5084 The `cleanup_undefined_types' bug that many of you noticed has been squashed.
5085 Many assorted bugs have been handled. Many more remain to be handled.
5086 See the various ChangeLog files (primarily in gdb and bfd) for details.
5089 *** Changes in GDB-4.3:
5091 * New machines supported (host and target)
5093 Amiga 3000 running Amix m68k-cbm-svr4 or amix
5094 NCR 3000 386 running SVR4 i386-ncr-svr4 or ncr3000
5095 Motorola Delta 88000 running Sys V m88k-motorola-sysv or delta88
5097 * Almost SCO Unix support
5099 We had hoped to support:
5100 SCO Unix on i386 IBM PC clones i386-sco-sysv or i386sco
5101 (except for core file support), but we discovered very late in the release
5102 that it has problems with process groups that render gdb unusable. Sorry
5103 about that. I encourage people to fix it and post the fixes.
5105 * Preliminary ELF and DWARF support
5107 GDB can read ELF object files on System V Release 4, and can handle
5108 debugging records for C, in DWARF format, in ELF files. This support
5109 is preliminary. If you bring up GDB on another SVR4 system, please
5110 send mail to bug-gdb@prep.ai.mit.edu to let us know what changes were
5115 GDB now uses the latest `readline' library. One user-visible change
5116 is that two tabs will list possible command completions, which previously
5117 required typing M-? (meta-question mark, or ESC ?).
5121 The `stepi' bug that many of you noticed has been squashed.
5122 Many bugs in C++ have been handled. Many more remain to be handled.
5123 See the various ChangeLog files (primarily in gdb and bfd) for details.
5125 * State of the MIPS world (in case you wondered):
5127 GDB can understand the symbol tables emitted by the compilers
5128 supplied by most vendors of MIPS-based machines, including DEC. These
5129 symbol tables are in a format that essentially nobody else uses.
5131 Some versions of gcc come with an assembler post-processor called
5132 mips-tfile. This program is required if you want to do source-level
5133 debugging of gcc-compiled programs. I believe FSF does not ship
5134 mips-tfile with gcc version 1, but it will eventually come with gcc
5137 Debugging of g++ output remains a problem. g++ version 1.xx does not
5138 really support it at all. (If you're lucky, you should be able to get
5139 line numbers and stack traces to work, but no parameters or local
5140 variables.) With some work it should be possible to improve the
5143 When gcc version 2 is released, you will have somewhat better luck.
5144 However, even then you will get confusing results for inheritance and
5147 We will eventually provide full debugging of g++ output on
5148 DECstations. This will probably involve some kind of stabs-in-ecoff
5149 encapulation, but the details have not been worked out yet.
5152 *** Changes in GDB-4.2:
5154 * Improved configuration
5156 Only one copy of `configure' exists now, and it is not self-modifying.
5157 Porting BFD is simpler.
5161 The `step' and `next' commands now only stop at the first instruction
5162 of a source line. This prevents the multiple stops that used to occur
5163 in switch statements, for-loops, etc. `Step' continues to stop if a
5164 function that has debugging information is called within the line.
5168 Lots of small bugs fixed. More remain.
5170 * New host supported (not target)
5172 Intel 386 PC clone running Mach i386-none-mach
5175 *** Changes in GDB-4.1:
5177 * Multiple source language support
5179 GDB now has internal scaffolding to handle several source languages.
5180 It determines the type of each source file from its filename extension,
5181 and will switch expression parsing and number formatting to match the
5182 language of the function in the currently selected stack frame.
5183 You can also specifically set the language to be used, with
5184 `set language c' or `set language modula-2'.
5188 GDB now has preliminary support for the GNU Modula-2 compiler,
5189 currently under development at the State University of New York at
5190 Buffalo. Development of both GDB and the GNU Modula-2 compiler will
5191 continue through the fall of 1991 and into 1992.
5193 Other Modula-2 compilers are currently not supported, and attempting to
5194 debug programs compiled with them will likely result in an error as the
5195 symbol table is read. Feel free to work on it, though!
5197 There are hooks in GDB for strict type checking and range checking,
5198 in the `Modula-2 philosophy', but they do not currently work.
5202 GDB can now write to executable and core files (e.g. patch
5203 a variable's value). You must turn this switch on, specify
5204 the file ("exec foo" or "core foo"), *then* modify it, e.g.
5205 by assigning a new value to a variable. Modifications take
5208 * Automatic SunOS shared library reading
5210 When you run your program, GDB automatically determines where its
5211 shared libraries (if any) have been loaded, and reads their symbols.
5212 The `share' command is no longer needed. This also works when
5213 examining core files.
5217 You can specify the number of lines that the `list' command shows.
5220 * New machines supported (host and target)
5222 SGI Iris (MIPS) running Irix V3: mips-sgi-irix or iris
5223 Sony NEWS (68K) running NEWSOS 3.x: m68k-sony-sysv or news
5224 Ultracomputer (29K) running Sym1: a29k-nyu-sym1 or ultra3
5226 * New hosts supported (not targets)
5228 IBM RT/PC: romp-ibm-aix or rtpc
5230 * New targets supported (not hosts)
5232 AMD 29000 embedded with COFF a29k-none-coff
5233 AMD 29000 embedded with a.out a29k-none-aout
5234 Ultracomputer remote kernel debug a29k-nyu-kern
5236 * New remote interfaces
5242 *** Changes in GDB-4.0:
5246 Wide output is wrapped at good places to make the output more readable.
5248 Gdb now supports cross-debugging from a host machine of one type to a
5249 target machine of another type. Communication with the target system
5250 is over serial lines. The ``target'' command handles connecting to the
5251 remote system; the ``load'' command will download a program into the
5252 remote system. Serial stubs for the m68k and i386 are provided. Gdb
5253 also supports debugging of realtime processes running under VxWorks,
5254 using SunRPC Remote Procedure Calls over TCP/IP to talk to a debugger
5255 stub on the target system.
5257 New CPUs supported include the AMD 29000 and Intel 960.
5259 GDB now reads object files and symbol tables via a ``binary file''
5260 library, which allows a single copy of GDB to debug programs of multiple
5261 object file types such as a.out and coff.
5263 There is now a GDB reference card in "doc/refcard.tex". (Make targets
5264 refcard.dvi and refcard.ps are available to format it).
5267 * Control-Variable user interface simplified
5269 All variables that control the operation of the debugger can be set
5270 by the ``set'' command, and displayed by the ``show'' command.
5272 For example, ``set prompt new-gdb=>'' will change your prompt to new-gdb=>.
5273 ``Show prompt'' produces the response:
5274 Gdb's prompt is new-gdb=>.
5276 What follows are the NEW set commands. The command ``help set'' will
5277 print a complete list of old and new set commands. ``help set FOO''
5278 will give a longer description of the variable FOO. ``show'' will show
5279 all of the variable descriptions and their current settings.
5281 confirm on/off: Enables warning questions for operations that are
5282 hard to recover from, e.g. rerunning the program while
5283 it is already running. Default is ON.
5285 editing on/off: Enables EMACS style command line editing
5286 of input. Previous lines can be recalled with
5287 control-P, the current line can be edited with control-B,
5288 you can search for commands with control-R, etc.
5291 history filename NAME: NAME is where the gdb command history
5292 will be stored. The default is .gdb_history,
5293 or the value of the environment variable
5296 history size N: The size, in commands, of the command history. The
5297 default is 256, or the value of the environment variable
5300 history save on/off: If this value is set to ON, the history file will
5301 be saved after exiting gdb. If set to OFF, the
5302 file will not be saved. The default is OFF.
5304 history expansion on/off: If this value is set to ON, then csh-like
5305 history expansion will be performed on
5306 command line input. The default is OFF.
5308 radix N: Sets the default radix for input and output. It can be set
5309 to 8, 10, or 16. Note that the argument to "radix" is interpreted
5310 in the current radix, so "set radix 10" is always a no-op.
5312 height N: This integer value is the number of lines on a page. Default
5313 is 24, the current `stty rows'' setting, or the ``li#''
5314 setting from the termcap entry matching the environment
5317 width N: This integer value is the number of characters on a line.
5318 Default is 80, the current `stty cols'' setting, or the ``co#''
5319 setting from the termcap entry matching the environment
5322 Note: ``set screensize'' is obsolete. Use ``set height'' and
5323 ``set width'' instead.
5325 print address on/off: Print memory addresses in various command displays,
5326 such as stack traces and structure values. Gdb looks
5327 more ``symbolic'' if you turn this off; it looks more
5328 ``machine level'' with it on. Default is ON.
5330 print array on/off: Prettyprint arrays. New convenient format! Default
5333 print demangle on/off: Print C++ symbols in "source" form if on,
5336 print asm-demangle on/off: Same, for assembler level printouts
5339 print vtbl on/off: Prettyprint C++ virtual function tables. Default is OFF.
5342 * Support for Epoch Environment.
5344 The epoch environment is a version of Emacs v18 with windowing. One
5345 new command, ``inspect'', is identical to ``print'', except that if you
5346 are running in the epoch environment, the value is printed in its own
5350 * Support for Shared Libraries
5352 GDB can now debug programs and core files that use SunOS shared libraries.
5353 Symbols from a shared library cannot be referenced
5354 before the shared library has been linked with the program (this
5355 happens after you type ``run'' and before the function main() is entered).
5356 At any time after this linking (including when examining core files
5357 from dynamically linked programs), gdb reads the symbols from each
5358 shared library when you type the ``sharedlibrary'' command.
5359 It can be abbreviated ``share''.
5361 sharedlibrary REGEXP: Load shared object library symbols for files
5362 matching a unix regular expression. No argument
5363 indicates to load symbols for all shared libraries.
5365 info sharedlibrary: Status of loaded shared libraries.
5370 A watchpoint stops execution of a program whenever the value of an
5371 expression changes. Checking for this slows down execution
5372 tremendously whenever you are in the scope of the expression, but is
5373 quite useful for catching tough ``bit-spreader'' or pointer misuse
5374 problems. Some machines such as the 386 have hardware for doing this
5375 more quickly, and future versions of gdb will use this hardware.
5377 watch EXP: Set a watchpoint (breakpoint) for an expression.
5379 info watchpoints: Information about your watchpoints.
5381 delete N: Deletes watchpoint number N (same as breakpoints).
5382 disable N: Temporarily turns off watchpoint number N (same as breakpoints).
5383 enable N: Re-enables watchpoint number N (same as breakpoints).
5386 * C++ multiple inheritance
5388 When used with a GCC version 2 compiler, GDB supports multiple inheritance
5391 * C++ exception handling
5393 Gdb now supports limited C++ exception handling. Besides the existing
5394 ability to breakpoint on an exception handler, gdb can breakpoint on
5395 the raising of an exception (before the stack is peeled back to the
5398 catch FOO: If there is a FOO exception handler in the dynamic scope,
5399 set a breakpoint to catch exceptions which may be raised there.
5400 Multiple exceptions (``catch foo bar baz'') may be caught.
5402 info catch: Lists all exceptions which may be caught in the
5403 current stack frame.
5406 * Minor command changes
5408 The command ``call func (arg, arg, ...)'' now acts like the print
5409 command, except it does not print or save a value if the function's result
5410 is void. This is similar to dbx usage.
5412 The ``up'' and ``down'' commands now always print the frame they end up
5413 at; ``up-silently'' and `down-silently'' can be used in scripts to change
5414 frames without printing.
5416 * New directory command
5418 'dir' now adds directories to the FRONT of the source search path.
5419 The path starts off empty. Source files that contain debug information
5420 about the directory in which they were compiled can be found even
5421 with an empty path; Sun CC and GCC include this information. If GDB can't
5422 find your source file in the current directory, type "dir .".
5424 * Configuring GDB for compilation
5426 For normal use, type ``./configure host''. See README or gdb.texinfo
5429 GDB now handles cross debugging. If you are remotely debugging between
5430 two different machines, type ``./configure host -target=targ''.
5431 Host is the machine where GDB will run; targ is the machine
5432 where the program that you are debugging will run.